Patent Grant
11692800
This application is a 35 U.S.C. 371 national stage filing from International Application No. PCT/EP2020/055582, filed Mar. 3, 2020, which claims priority to European Application No. 19446501.9, filed Mar. 4, 2019, the teachings of which are incorporated herein by reference.
The present invention relates to a safety and arming unit for initiation of underwater charges. In particular, the present invention relates to a safety and arming unit for initiation of underwater charges suitable for underwater ordnance, such as mines, clearance.
Underwater ordnance disposal systems are known. For example, traditional mine sweeping vessels drag either lines to mechanically trigger the ordnance or a decoy to remotely trigger the ordnance for example by simulating the magnetic or acoustic signature of a vessel being targeted by the ordnance. This type of mine sweeping is dangerous as it requires the vessel to enter the area containing the ordnance. In addition, unsweepable ordnance has been developed which prevents the use of such a system.
Other types of ordnance disposal systems are known, and enable remote, i.e. remote from a vessel such as a mine countermeasures vessel (MCMV), operation. Examples of such known systems are diver placed charges, remotely operated single charge systems, and multiple charge deployment systems.
Also known are means for ensuring that the clearance charge is safe to handle, and only placed in an armed state after certain operations have been carried out, and only in certain conditions. For example, hydrostatic arming units are well-known, which only arm the clearance charge upon the clearance charge being below a certain depth of water. Other more complex safety and arming units are known, such as that disclosed in EP 0 075 496 A1. The system of EP 0 075 496 A1 comprises a movable rotor which forms a screen across a pyrotechnic firing chain, the rotor being locked by a shaft movable under the influence of external water pressure. Movement of the shaft initiates an inter-related chain of events that results in the arming of the charge device.
It is therefore an object of the present invention to provide an improved safety and arming unit. It may also an object of the present invention to provide a safety and arming unit that complies with the requirements of AOP-15 (third edition) and AOP-16 (fourth edition).
According to a first aspect of the present invention, there is provided a safety and arming unit for initiation of underwater charges, comprising: a housing; a detonator; an interrupter slidable within the housing from a first position in which a firing chain from the detonator to a charge is interrupted, to a second position, in which the firing chain is complete; a first member configured to cooperate with the housing and the interrupter to form a first interlock, wherein, upon the first member being in a first position, said interlock locks said interrupter in said first position, and upon the first member being in a second position, said interrupter is free to slide relative to said first member; a second member configured to cooperate with the housing and the interrupter to form a second interlock, mechanically independent of said first interlock, wherein, upon the second member being in a first position, the interlock locks said interrupter in said first position, and upon the second member being in a second position, said interrupter is free to slide relative to said second member; and a plurality of electrical switches arranged in series, switchable from a first configuration in which the detonator is electrically isolated from a remote initiation firing system, to a second configuration in which the detonator is in electrical communication with a remote initiation firing system. Upon the first member being in the second position, and the second member being in the second position, the interrupter is slidable from the first position to the second position upon being subjected to an external water pressure greater than a threshold value. Upon the interrupter being in the second position, the interrupter acts on the plurality of electrical switches to switch said plurality of switches to said second configuration.
Advantageously, by providing a system having a plurality of safety features, in the form of a removable pin, first and second locks and a plurality of switches arranged in series, each released, triggered or activated by independent events, a safety and arming unit which reduces the risk of accidental arming and firing is provided.
Preferably, the threshold value is about 3 mwc, but may be any suitable value, such as 6 mwc, 10 mwc, or 20 mwc depending on the requirements of the particular use case for the safety and arming unit. Preferably, the interrupter is resiliently biased towards the first position. The threshold value is preferably determined by the stiffness of the resilient biasing means. The resilient biasing means is preferably a spring, more preferably a helical spring. The housing preferably further comprises a diaphragm configured to form a seal between an end of the interrupter and the housing. The, flexible, diaphragm is configured to maintain the seal between the interrupter and the housing upon relative movement between the two.
Preferably, the safety and arming unit further comprises a mechanical actuator configured to move said first member from said first position to said second position, more preferably said mechanical actuator comprises a lever, pivoted about a fulcrum on said housing. The lever is preferably configured as a cam lever, the cam surface acting on the first member. The first member is preferably configured to slide linearly, and preferably perpendicularly to, the interrupter.
The first member preferably has a first end and a second end. The first end being configured to be acted upon by said lever, the second end comprising at least one projection. In this embodiment, the interrupter comprises an elongate slot and corresponding protrusion configured to partially cover the slot. The slot and protrusion preferably having a cross-sectional shape substantially corresponding to the cross-sectional shape of the second end of the first member. The protrusion comprising at least one notch configured to engage with the at least one projection of the second end of the first member to lock the interrupter in its first position upon the first member being in its first position.
In one example, the second end of the first member comprises a circular projection configured such that the second end is in the form of a T-piece, the elongate slot and protrusion being a T-groove. Alternatively, the second end of the first member comprises two opposed projections configured such that the second end is in the form of a T-piece, the elongate slot and protrusion being a T-groove. Further examples, such as a single elongate projection may be provided at the second end of the first member such that the second end is in the form of a L-piece, the elongate slot and protrusion having a corresponding shape. In each example, the at least one notch in the protrusion partially covering the slot preferably has a shape corresponding to the shape of the second end of the first member.
Preferably, the safety and arming unit further comprises a line having a first end releasably coupled to said mechanical actuator, and a second end configured to be coupled to a deployment device configured to deploy an underwater charge coupled to the safety and arming unit. In this way, the mechanical actuator may be configured to move said first member from the first position to the second position upon release and separation of the underwater charge coupled to the safety and arming unit from the deployment device. Preferably, the line is in the form of a lanyard. In one example, the mechanical actuator comprises a recess, preferably in the form of a notch, configured to receive a loop provided on the line, to releasably couple the line to the actuator. The line may be between about 300 mm and about 1500 mm in length, preferably between about 500 mm and about 1000 mm in length.
Preferably, said first member is retained in said first position by a detent. The detent is preferably a frangible member. In this way, the safety and arming unit may provide a reduced risk of unintentional arming. The frangible member is preferably a shear-pin, preferably formed of Brass, or Aluminium. Alternatively, the detent comprises at least one resiliently biased pin configured to engage with a corresponding recess in the housing, the at least one pin being biased towards engagement with said recess. The or each pin preferably has a rounded end configured to engage with the recess, the recess having a corresponding shape. The detent may comprise two such resiliently biased pins, provided on opposed sides of the first member. The detent may comprise four such resiliently biased pins, provided orthogonal to each other about the first member. As will be appreciated, the force required to overcome the biasing force to release the or each pin from the or each recess is equivalent to the force required to break the frangible member described above.
Preferably, the safety and arming unit further comprises an electrically actuated actuator configured to move said second member from said first position to said second position, preferably said electrically actuated actuator is a pyrotechnic piston actuator.
The second member is preferably configured to slide linearly, and preferably perpendicularly to, the interrupter. The first member and second member are preferably arranged such that the vector defining movement of the first member is not aligned with the vector defining movement of the second member. Preferably, the first member is provided on a side of the interrupter opposite to a side where the second member is provided, the first member and the second member being arranged such that the direction of movement from the first position to the second position is substantially radial towards the longitudinal axis of the interrupter. Advantageously, this reduces the risk that external forces acting on the safety and arming unit cause both the first member and second member to move from the first position to the second position.
The second member preferably has a first end and a second end. The first end being configured to be acted upon by said electrically actuated actuator, the second end comprising at least one projection. In this embodiment, the interrupter comprises a further elongate slot and corresponding protrusion configured to partially cover the slot. The slot and protrusion preferably having a cross-sectional shape substantially corresponding to the cross-sectional shape of the second end of the second member. The protrusion comprising at least one notch configured to engage with the at least one projection of the second end of the second member to lock the interrupter in its first position upon the second member being in its first position.
In one example, the second end of the second member comprises a circular projection configured such that the second end is in the form of a T-piece, the further elongate slot and protrusion being a T-groove. Alternatively, the second end of the second member comprises two opposed projections configured such that the second end is in the form of a T-piece, the further elongate slot and protrusion being a T-groove. Further examples, such as a single elongate projection may be provided at the second end of the second member such that the second end is in the form of a L-piece, the further elongate slot and protrusion having a corresponding shape. In each example, the at least one notch in the protrusion partially covering the slot preferably has a shape corresponding to the shape of the second end of the second member.
Preferably, said second member is retained in said first position by a further detent. The further detent is preferably a frangible member. In this way, the safety and arming unit may provide a reduced risk of unintentional arming. The frangible member is preferably a shear-pin, preferably formed of Brass, or Aluminium. Alternatively, the further detent comprises at least one resiliently biased pin configured to engage with a corresponding recess in the housing, the at least one pin being biased towards engagement with said recess. The detent may comprise two such resiliently biased pins, provided on opposed sides of the second member. The detent may comprise four such resiliently biased pins, provided orthogonal to each other about the second member. As will be appreciated, the force required to overcome the biasing force to release the or each pin from the or each recess is equivalent to the force required to break the frangible member described above.
Preferably, the safety and arming unit further comprises at least one controller, the or each controller comprising an arming timer configured to output an arming signal after a predetermined period of time, wherein said arming timer is initiated upon the first member being moved to said second position, the arming signal being configured to actuate the electrically actuated actuator. The predetermined period of time may be between about 5 minutes and about 30 minutes, preferably between about 10 minutes and about 20 minutes. In one particular embodiment, the predetermined period of time is about 15 minutes. Advantageously, providing a delay between movement of the first member to said second position, and actuating the electrically actuated actuator to move the second member to said second position, may provide increased safety and enable sufficient time for a deployment vehicle to withdraw to a safe distance before the interrupter may move to the second position to complete the firing chain. The safety and arming unit may comprise two such controllers, each comprising an arming timer configured to output an arming signal after a predetermined period of time. Each controller is preferably configured to be independent of the other. In this way, a safety and arming unit is provided which has in-built redundancy to decrease the failure rate of the unit.
The safety and arming unit preferably comprises a timer initiation electrical switch configured to be switched upon movement of the first member from the first position to the second position. The timer initiation electrical switch is preferably a micro-switch.
Preferably, said plurality of electrical switches are configured in at least two sets, the sets being disposed about the longitudinal axis of the interrupter. The two sets of switches preferably being disposed orthogonally about the longitudinal axis of the interrupter. In this way, the risk of accidental actuation of all switches due to impact forces, vibrational forces, etc, may be reduced. In the first configuration, at least one electrical switch is preferably configured to short-circuit firing leads for the detonator. In the first configuration, at least one electrical switch, preferably two electrical switches, are preferably configured to electrically connect a remote initiation firing system to electrical ground.
Preferably, each set of electrical switches comprises two electrical switches. For ease of reference, the following nomenclature will be used: the first set comprises electrical switch S1 and electrical switch S3, and the second set comprises electrical switch S2 and electrical switch S4. In one example, in the first configuration, one electrical switch, S1, from the first set and one electrical switch, S2, from the second set are each configured to electrically connect one of two electrical lines of a remote initiation firing system to electrical ground. In the second configuration, a first electrical line of a remote initiation firing system is electrically connected to the detonator by electrical switches S1 and S3 in series, and a second electrical line of a remote initiation firing system is electrically connected to the detonator by electrical switches S2 and S4 in series.
The safety and arming unit preferably further comprises at least one electrical filter connected to the plurality of electrical switches, such that upon connection to a remote initiation firing system the signals received from said remote initiation firing system are filtered. Preferably, the at least one electrical filter is a low-pass filter, more preferably the electrical low-pass filter is a Pi-filter.
Preferably, the safety and arming unit further comprises a removable pin configured to engage with the housing and the interrupter to lock said interrupter in said first position. The safety and arming unit may further comprise a positively buoyant body flexibly coupled to said removable pin. The positively buoyant body being sufficiently positively buoyant such that upon deployment of the safety and arming unit coupled to a clearance charge the positively buoyant body acts to remove said removable pin and unlock said interrupter. The safety and arming unit may further comprise a further removable pin configured to engage with the housing and the positively buoyant body to lock said positively buoyant body to said housing during transport. The positively buoyant body is preferably a float formed of rigid foam, a substantially hollow body formed of a plastic, or polyethylene.
Preferably, the safety and arming unit further comprises at least one removable transport pin configured to engage with the housing and the interrupter to lock said interrupter in said first position. The removable transport pin may comprises a highly visible tag. The removable transport pin may be removed prior to deployment of the safety and arming unit, and may reduce the risk of unintentional arming yet further.
Preferably, the safety and arming unit further comprises a sterilisation system configured to permanently lock said interrupter in a sterilised position in which a firing chain from the detonator to a charge is interrupted, said sterilisation system comprising: a sterilisation timer configured to initiate the sterilisation system after a predetermined period of time; means to move the interrupter from said second position to said sterilised position; and a lock configured to cooperate with the housing and the interrupter to lock said interrupter in said sterilised position. Where the safety and arming unit comprises at least one controller, the or each controller further comprises a sterilisation timer. The sterilisation timer may be the same timer as the arming timer, or it may be a separate timer. The predetermined period of time before initiating the sterilisation system may be between about 1 hour and about 12 hours, preferably between about 3 hours and about 9 hours, and in one preferred embodiment the period of time is about 6 hours.
Preferably, said means to move the interrupter comprises an electrically actuated gas generator. The electrically actuated gas generator is preferably sealed within the housing adjacent an end of the interrupter. The gas generator is preferably configured to generate a pressure within the housing of at least about 100 mwc, or at least about 200 mwc, or at least about 500 mwc. In one preferred embodiment, the safety and arming unit is designed for a maximum operational depth of 300 m, and so the gas generator is configured to generate a pressure within the housing of at least about 350 mwc. As will be appreciated, the pressure generate by the gas generator is chosen in dependence on the operational depth of the safety and arming unit. Where the interrupter is resiliently biased towards the first position, the gas generator is configured to cooperate with said resilient biasing to move said interrupter against the external water pressure.
Preferably, said sterilisation lock comprises a sprung clip, configured to engage with a through hole in the housing. The sterilisation lock may further comprise at least one pin, provided in said housing, resiliently biased towards said interrupter, the interrupter comprising a corresponding recess configured to receive said pin upon said interrupter being in said sterilised position. The at least one pin is preferably movable in a direction perpendicular to the longitudinal axis of the interrupter. The lock may comprise two, or more, such pins.
Preferably, the safety and arming unit further comprises: first indicia configured to indicate that the interrupter is in the first position; and second indicia configured to indicate that the interrupter is in the second position. When the safety and arming unit comprises a sterilisation system, the unit preferably further comprises third indicia configured to indicate that the interrupter is in the sterilised position. The indicia are preferably in the form of at least one of: colour; numerals; letters; and symbols. In one example, the first indicia is green, and/or the letter “S”, the second indicia is red, and/or the letter “A”, and the third indicia is yellow.
As used herein, the term interrupted explosive train, or interrupted firing chain, is an explosive train in which the explosive path between the detonator and the primary explosive charge is functionally separated until arming. This configuration prevents the detonation wave propagating from the detonator to the primary explosive charge even if the detonator should function.
Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination.
It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.
The invention will be further described, by way of example only, with reference to the accompanying drawings in which:
The safety and arming unit of the present disclosure is configured to be coupled to a clearance charge for clearing underwater ordnance, such as mines. The combination of the safety and arming unit, a clearance charge, means for attaching the clearance charge to the ordnance, a float (i.e. a positively buoyant body), and a remote initiation firing system is referred to herein as a Mine Neutralisation System (MNS). The MNS may be carried to the ordnance by a remotely operated vehicle (ROV), and then deployed. Before detonating the clearance charge, the ROV retreats to a safe distance. To prevent unintentional detonation, the safety and arming unit is provided with various safety and interlock features, as described below with reference to the appended figures. For ease of reference the safety and arming unit is referred to herein as SAU. The SAU provides for three configurations, safe, armed, and sterilised.
During transport by the ROV to the ordnance, the MNS is housed in a silo mounted to the ROV. Upon deployment, the float is released which releases an electric firing cable connecting the SAU and clearance charge to the remote initiation firing system. The remote initiation firing system is buoyant, or may simply be attached to the float, and so floats upwards to the water surface where it may receive an initiation signal (i.e. a firing signal). The SAU is configured such that only upon being in the armed configuration will a firing signal received from the remote initiation firing system trigger the detonator. It is noted that the SAU may be provided with a float transport pin, configured to lock the float to the SAU housing while being handled and mounted into the ROV silo. The float transport pin is removed before the ROV is launched.
The interrupter is held in a safe, first, position by several independent safety features, some of which can be seen in
A further safety feature can be seen in
The SAU 100 is also provided with an indicator system for visually indicating to a user which configuration the SAU is in. The hole 122 enables a portion of the interrupter, comprising indicia, to be visible from outside of the housing 102. The indicia on the interrupter provide a visible indicator as to the configuration of the SAU 100; in the safe state, a green “S” is visible, and in the armed state, a red “A” is visible. A further indicator is provided on the interrupter to indicate when the SAU 100 is in the sterilised state. The further, sterilised, indicator is a yellow portion which protrudes from hole 124 upon the SAU 100 being in the sterilised state.
Before describing the details of the SAU 100, reference is made to
As described above, the interrupter 404 is prevented from moving to the “armed” state by various safety features, which are shown schematically in
Once all four safety features have been activated, the interrupter 404 is slidable from the “safe” state to the “armed” state under the influence of an external water pressure of 3 mwc; the SAU 100 may be configured to be armed at any other suitable water depth. The spring 418 biases the interrupter towards the “safe” position and so as will be appreciated the depth of water required to arm the SAU is determined by the spring constant of spring 418. Upon movement of the interrupter 404 from the “safe” state to the “armed” state, the visual indicator 420 (a green “S”) moves from visibility within the hole 122, and the visual indicator 422 (a red “A”) becomes visible.
In addition, upon movement of the interrupter 404 from the “safe” state to the “armed” state, the electrical switches 424 are switched such that a remote initiation firing system 426 is electrically connected to the detonator 400 via a twisted pair cable 428; in this example, a bobbin of twisted pair cable of 415 m length is provided. Thus, upon receipt of a firing signal the remote initiation firing system sends a signal to the detonator 400 to detonate, thus initiating the clearance charge 402.
The remote initiation firing system 426 in one example is a Mini DFRD M3.0, manufactured by MAS Zengrange (NZ Ltd). The Mini-DRFD system is designed to remotely detonate munitions and explosives either by radio signals. The Mini-DRFD operates by using a UHF radio link from transmitter to receivers thereby over-coming the disadvantages associated with hardwire-based systems.
The detonator 400 has a low magnetic signature so as not to be detected by magnetic sensors in the ordnance. In addition, the detonator is sensitive enough to be fired from a Mas Zengrange Receiver 426 via the long firing cable 428, and sufficiently powerful to initiate the clearance charge without a lead or booster. The detonator 400 is preferably qualified according to STANAG 4560/AOP-43 and STANAG 4170. One such suitable detonator is L2A2, manufactured by Chemring and is in service with the UK MoD. The L2A2 contains 1.1 g PETN. The No Fire Current is 0.3 A max and the shelf life is 5 years.
The clearance charge 402, in one example, is a shaped charge with a copper cone to form a jet suitable for penetrating the ordnance. The pre-filled main charge is FPX R1M, a Plastic Bonded Explosive that is qualified according to STANAG 4170.
As mentioned above, deployment of the MNS by the ROV 410 starts an arming timer. In addition, a sterilisation timer is started, and after 6 hours if the SAU has not received a firing signal from the remote initiation firing system 426, a gas generator 430 is actuated to pressurise the housing and force the interrupter 404 against the external water pressure such that the interrupter is moved to a “sterilised” state. In this “sterilised” state the interrupter 404 is permanently locked by a latching lock on the interrupter which engages with the housing such that it cannot move back to the “armed” state. In addition, a sterilisation indicator 432 becomes visible out of hole 124.
Further structural features of the SAU 100 will now be described with reference to
A micro-switch 508 is provided in a sub-housing 510, which also rotatably supports the lever 118, and a lever lock member (not shown). As described above, moving the lever 118 to the second position acts to move the lock member to a second position and unlock the interrupter 404. At the same time, the micro-switch is activated.
In this example, the two microprocessors, type ATtiny24 and −44, are configured to operate in parallel, (OR-configuration). This configuration is chosen in order to maximise the functionality. Both micro-processors can individually fire the protractor 416 for arming and the gas generator 430 for sterilisation, hence increasing the function probability. When the micro-switch 508 is activated on deployment (the lanyard is pulled by the ROV) the timers in the processors start counting. To avoid resetting the counter to zero in case of a power failure, the counter value is stored in a non-volatile memory (the internal EEPROM) every two seconds and if there is a power interruption or a reset due to any reason when the timer is running, the count will continue from the last stored value. As described above, upon the arming timer reaching 15 minutes the protractor is triggered, and then upon the sterilisation timer reaching 6 hours the gas generator is triggered if the firing signal has not been received, or if the detonator did not function as intended. Further detail regarding the timing circuit is provided below with reference to
Once the protractor 416 has been actuated, the interrupter 404 is free to move from the first, “safe,” position to the second, “armed”, position. However, it will only do so once the SAU is at least under the equivalent external pressure of 3 mwc. Various cover plates and seals are provided to prevent the ingress of water into the housing, and thus enable a pressure differential between an external portion of the interrupter at a first end thereof and an internal portion of the interrupter at a second end thereof. In addition to the seals described above, the detonator 400 is sealed within the housing by cover plate 512, the second end of the interrupter 404 upon which the spring 418 acts is sealed within a chamber by cover plate 514, and a flexible diaphragm 516 is provided at the first end of the interrupter 404 to enable the interrupter 404 to slide while a seal is maintained.
Upon the interrupter 404 sliding to the second, “armed”, position the electrical switches 424 are activated. As can be seen, the switches 424 are provided in two sets, 424a and 424b, the switches being mounted orthogonal each other on mounting plate 518. Mounting the switches in this manner reduces the risk of activation of all switches due to vibration or impact forces. Further detail of the firing circuit is provided below with reference to
Looking now to
As described above, the interrupter is provided with a sterilisation lock 608 which is in the form of a sprung latch. Upon sterilisation the sterilisation lock 608 is forced through the hole 124, and the sprung latch engages with the external wall of the housing. In addition, an annular groove 610 is provided, which upon the interrupter 404 moving to the sterilised position, receives a sterilisation lock pin (not shown), the pin being resiliently biased towards the interrupter 404.
Further detail of the lever lock member 906 are shown in
Also shown more clearly in
As described above, 6 hours after initiation of the sterilisation timer the gas generator 430 is actuated to place the SAU in the “sterilised” state.
Further detail will now be provided regarding the “armed” state, with reference to
As described above, if the firing signal is not received within 6 hours, the timing circuit actuates the gas generator to sterilise the SAU. The “sterilised” state is shown in
Similarly, just before the sterilisation timer reaches 6 hours, the DC/DC-converter 1704 starts and generates 15 volts, the firing capacitor 1706 is charged and after a short delay, the field effect transistor (FET) opens and the gas generator 430 is fired. The micro-processors provide a gas generator fire signal repeatedly until the battery 502 can no longer provide sufficient power to reduce the risk that the gas generator is not actuated. The FET 1708 ensures that the firing capacitor 1706 is isolated after a firing, since there is no guarantee that the protractor or gas generator will be open-circuit after a firing and the thyristor 1712 must be commutated for the firing capacitor to recharge.
All components of the electronic controller 500 are chosen for low magnetic signature, including the ferrite, switches, connectors and the battery.
To reduce the risk of a common cause batch failure, the two micro-processors 1700, 1702 are of different types with the only difference in memory size (ATtiny24 and ATtiny44), the software is however exactly the same in both devices. The software is basically a state machine with no nested interrupts. The two processors work in lock-step with a time difference of 24 seconds, to prevent any collision of signals. The processor oscillators are controlled by one 4 MHz crystal for each processor. The crystal accuracy is 50 ppm which results in a maximum error of ±1.08 second over 6 hours. If the micro-processor restarts after it has first been powered-up, the last time saved is read and the program continues from that time. In the event of a restart the maximum time error is 2 seconds+the time of the power outage.
Each micro-processor has its own external reset device that ensures that the processor starts in a controlled way after power-up and power-glitches, black-out or brown-out. The internal watchdog supervises the program flow, and in the case of a lock-up, it will restart the processor.
Finally, the firing circuit will be described with reference to
In
The embodiments and examples described above illustrate but do not limit the invention. It will be appreciated that other embodiments of the invention may be made and it is to be understood that the specific embodiments described herein are not intended to be limiting.
| Number | Date | Country | Kind |
|---|---|---|---|
| 19446501 | Mar 2019 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/055582 | 3/3/2020 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2020/178292 | 9/10/2020 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3195460 | Kalaf | Jul 1965 | A |
| 3532057 | Aubrey | Oct 1970 | A |
| 3782282 | Bjork | Jan 1974 | A |
| 4111125 | Reineke | Sep 1978 | A |
| 4986184 | Kude | Jan 1991 | A |
| 5821447 | Reams | Oct 1998 | A |
| 6131516 | Sanford | Oct 2000 | A |
| 6173650 | Garvick | Jan 2001 | B1 |
| Number | Date | Country |
|---|---|---|
| 0075496 | Mar 1983 | EP |
| Entry |
|---|
| PCT International Search Report and Written Opinion dated Jun. 8, 2020 for Intl. App. No. PCT/EP2020/055582, from which the instant application is based, 10 pgs. |
| Number | Date | Country | |
|---|---|---|---|
| 20220178668 A1 | Jun 2022 | US |
