Method and Robotic System for 20mm Super Pull Apart Machine Autofeeding

Description

FIELD OF THE INVENTION

The present invention pertains to an autofeeding system designed for the demilitarization process of 20 mm rounds, including a robot depositing the 20 mm rounds into a bowl feeder for alignment, and subsequently feeding them into a Super Pull Apart Machine (SPAM). The 20 mm SPAM is responsible for extracting the projectiles for subsequent processing, such as recycling. Additionally, the system incorporates a control and management system to monitor, manage, and regulate the feeding process.

BACKGROUND OF THE INVENTION

Demilitarization of excess, obsolete, and unserviceable munitions is a critical step in the life-cycle management of unused munitions. The practices of demilitarization prioritize safety, security, and environmental responsibility as well as cost efficiency. Different demilitarization methods are employed for disposing of munitions, including closed disposal technologies, open burn, or open detonation, chosen depending on the types of munition.

The demilitarization of 20 mm rounds is among the top priorities at many munition depots. In the demilitarization process, 20 mm rounds are managed to feed into a Super Pull Apart Machine (SPAM) for safe disassembly in a closed environment. Specifically, SPAM for 20 mm demilitarization is a closed disposal disassembly machine that can reverse the assembly process to separates the projectile from the round. This disassembly process begins with one or more operators to feed 20 mm rounds into the SPAM's infeed in sequel. The infeed comprises a chain conveyor with cups for operators to deposit the rounds. Subsequently, SPAM extracts the projectiles and conveys them to the projectile collection and weighing area through a slotted conveyor. The powder generated during this process is collected, weighed, and discharged. The processed brass is collected for recycling. The primers are functioned and inspected by optical cameras.

Traditionally, human operates 20 mm rounds to feed them into the SPAM by manually placing ammunition onto the chain conveyor. Such a human-based approach poses critical health and safety risks for operators due to hazardous components, chemical exposure, and explosion hazards. Some munition problems, such as bad primers (e.g., corroded primers that are electrical initiated, primer burning instead of popping) and powder clumping, impose serious risks if the munition is detonated during the human process. Additionally, the manual feeding process increases the risk of repetitive strain injuries and accidents caused by human errors, potentially resulting in equipment damage or malfunction. Moreover, the human-based feeding approach not only incurs high operational costs but also lacks efficiency due to significant gaps between system safety limits and operational constraints.

BRIEF SUMMARY OF THE INVENTION

The method proposed in this invention aims at providing an automated way for feeding 20 mm rounds into the SPAM, which is to minimize the involvement of manual handling and processing of hazardous materials, thus reducing the risk of accidents and injuries. Additionally, the present invention reduces the number of operators in the demilitarization line, resulting in safe and economical demilitarization of the 20 mm munition stockpile of obsolete and non-serviceable munitions.

According to the first aspect of the present invention, there is provided a method of depositing 20 mm rounds from bins into the bowl feeder using a robotic system. The robotic system includes: (i) A heavy-duty robot arm capable of lifting a bin of a specific size, fully loaded with 20 mm rounds of the heaviest type; (ii) A customized fork-shaped gripper designed to pick up, rotate, and securely hold a bin during the feeding process; (iii) A control system for managing and coordinating the various functions and movements of the robot; and (iv) A vision system for bin detection, alignment, positioning, process monitoring, and providing real-time feedback to ensure operational efficiency and accuracy. Additionally, the robot can be configured as a mobile platform, enhancing its versatility and adaptability for various operational environments. This mobility enables the robot to navigate autonomously within the facility, efficiently accessing different bin locations and contributing to seamless integration with the overall ammunition feeding process.

According to the second aspect of the present invention, there is provided a method of aligning and releasing 20 mm rounds to the chain conveyor at a specified feed rate using a bowl feeder. The bowl feeder includes: (i) A bowl-shaped container designed to hold and orient the ammunition in a consistent manner; (ii) An internal mechanism for manipulating the position and orientation of the ammunition within the bowl, ensuring proper alignment and presentation for feeding; (iii) A discharge assembly for transferring the aligned ammunition from the bowl feeder to the transit slide; (iv) A transit slide that aligns and orients the rounds to ensure their tips point upwards at the outlet; (v) An outlet that aligns with the chain conveyor with mechanisms to precisely drop rounds into the cups of the chain conveyor at a preset feed rate; (vi) Adjustable controls for regulating the feed rate to accommodate the status of the SPAM; (vii) Integrated sensors and a vision system for detecting the presence or absence of 20 mm rounds at the outlet, controlling ammunition flow, synchronizing with the chain conveyor, monitoring ammunition flow, detecting jams or irregularities, and providing feedback for smooth operation. Additionally, the bowl feeder for 20 mm round can feature additional enhancements such as anti-jamming mechanisms, gates to control the flow of ammunition, and compatibility with the chain conveyor for seamless integration into the overall ammunition handling process.

According to the third aspect of the present invention, a control and management system is provided to communicate with the subcontrollers at the robots, bowl feeder, and chain conveyor, facilitating monitoring and control of the feeding process. Additionally, it grants operators the ability to monitor and regulate the feeding process through user interfaces. Data from vision systems and sensors, including status updates, are transmitted to the control and management system for analysis and adjustment, such as feed rate adjustments.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing the 20 mm SPAM autofeeding line of the present invention;

FIG. 2 is a perspective view of the robot;

FIG. 3 is a side view of the robot;

FIG. 4 is a perspective view of the bowl feeder;

FIG. 5 is an exploded perspective view of the bowl feeder;

FIG. 6 is a plan view of the 20 mm SPAM autofeeding line;

FIG. 7 is a flowchart which shows the operation of the 20 mm SPAM autofeeding line in an embodiment of the present invention;

FIG. 8 is a sequence diagram of an embodiment of the present invention during normal operation;

FIG. 9 is a flowchart which shows the operation of the robot;

FIG. 10 is a flowchart which shows the operation of the bowl feeder;

FIG. 11 is a flowchart which shows the operation of the chain conveyor;

FIG. 12 is a flowchart which shows the operation of the control and management system.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment in which the present invention can be used for automatically feeding the Super Pull Apart Machine (SPAM) in the 20 mm demilitarization process will be described below.

FIG. 1 shows an embodiment of feeding 20 mm rounds into the SPAM for disassembly. Given the loading area of the SPAM building, ammunition bins 1 containing 20 mm rounds are placed on pallets 2. To feed 20 mm round into the SPAM, a heavy-duty robot 3 picks up a bin 1 and deposits the 20 mm rounds into a bowl feeder 4. The bowl feeder 4 automatically and consistently aligns the rounds in the feeder bowl and orients rounds at the outlet with a transit slide. The end of the outlet has a tunnel that is aligned with the starting location of a cup 5 on the chain conveyor 6, which then transfers the 20 mm rounds into the SPAM 7. The frequency at which robot 3 retrieves bin 1 is synchronized with its capacity and the feed rate of bowl feeder 4 to prevent overfilling. Sensors and vision systems 8, along with controllers and their respective communication units 9, are integrated to monitor and manage the process flow. These components are stationed at various points including bin 1, robot 3, bowl feeder 4 and chain conveyor 6. A control and management system 10 communicates with the subcontrollers at the robot 3, bowl feeder 4, and chain conveyor 6, facilitating monitoring and control of the feeding process. Additionally, it allows operators to oversee and regulate the feeding process through user software, utilizing data collected by the sensors and vision systems 8. This includes information on bin status, bowl feeder status, chain conveyor status and SPAM throughput. Subsequently, the control and management system 10 sends actuating signals to the communication units 9 of the controllers to regulate the activities of the robot 3, the feed rate of bowl feeder 4, and the speed of chain conveyor 6.

FIG. 2 shows an embodiment of the perspective view of the robot 3. FIG. 3 shows an embodiment of the side view of the robot 3. Robot 3 can be an industrial-grade collaborative robot with either 6-axis or 7-axis configurations. A 6-axis robot provides six degrees of freedom or rotational joints, enabling movement in various directions, such as vertical (up and down), horizontal (side to side), and longitudinal (forward/backward), as well as rotation around three different axes. Conversely, a 7-axis robot features an additional joint that allows the end effector to rotate independently, offering enhanced flexibility and higher precision for ammunition bin handling. Robot 3 follows the ISO 8373 standard. Robot 3's payload capacity (the maximum weight that a robot arm can handle while maintaining its accuracy, speed, and safety) is determined by the maximum weight of bin 1 when fully loaded with ammunition. Robot 3's reach (the maximum distance from the base of the arm to the farthest point it can extend while still being able to perform its intended tasks accurately and safely) and physical dimensions (height, width, and depth) are determined by several factors. These include the distance between robot 3 and the bin 1 and bowl feeder 4, as well as the constraints of the application environment, particularly when space is limited. Robot 3 is equipped with a fork-shaped gripper 20, which is an end effector connected on the robot 3, to pick up bin 1, and deposit the ammunition into the bowl feeder 4. Robot 3 is controlled by an embedded robot system controller, which controls the robot arm and the gripper 20 by using industrial communication protocols. The coordinated control system integrates various components such as sensors, actuators, and controllers to ensure smooth operation of the robot. Communication protocols facilitate coordination between the robot and other system components such as the bowl feeder 4, and chain conveyor 6. Feedback loops allow the system to adjust robot movements based on real-time data from sensors and external signals. The control system ensures synchronization of robot activities with other system components to achieve the desired feeding process efficiently and accurately. This controller is housed within the controller cabinet 21, where it coordinates the robot 3's movements and functionalities. The controller encompasses a motion controller, along with internal and external communication units 9, and potential power stages. The internal communication unit facilitates data exchange between different modules within robot 3, ensuring effective coordination of activities among its components. The external communication unit enables robot 3 to transmit status updates and receive commands from the control and management system 10. Additionally, robot 3 can be equipped with an Automated Guided Vehicle (AGV) system, a mobile platform with wheels that enables autonomous navigation and ammunition bin picking within its environment, eliminating the need for an operator to position the bin in a fixed location.

FIG. 4 shows an embodiment of the perspective view of the bowl feeder 4. The bowl feeder 4 adapted for feeding 20 mm rounds to the chain conveyor is designed to sort, orient, and feed efficiently and accurately. The bowl feeder is a centrifugal bowl feeder to accommodate factors such as the large ammunition dimensions and weight of the 20 mm rounds, a feeding speed of 2 seconds per round, and precise orientation control to ensure the rounds are positioned with their tips pointing upward. A centrifugal feeder for feeding ammunition consists of a circular feeder bowl with a spiral track inside, mounted on a base. The bowl is typically made of durable materials such as stainless steel to withstand the weight and impact of ammunition. Ammunition parts are loaded into the bowl, where they accumulate randomly. The bowl rotates, generating centrifugal force that pushes the ammunition towards the outer edge of the bowl. Along the spiral track, there are features or mechanisms designed to orient the ammunition in a specific direction. These features ensure that the ammunition are correctly positioned for downstream processing. Once oriented, the ammunition reach the outer edge of the bowl and are discharged one by one. Centrifugal bowl feeders are favored for larger and heavier ammunition, offering higher feeding speeds. For this embodiment, a centrifugal bowl feeder is selected, with a size of at least 30 inches to meet the desired feeding speed. Customization options are available for the bowl feeder size to adapt to specific application needs, including feed rate adjustments. The bowl feeder wall 22 is constructed from stainless steel to ensure durability and corrosion resistance. The bowl feeder 4 is mounted to a custom height base stand 23 via a bowl feeder stand 24, providing flexibility for adjusting discharge height. The bowl feeder motor is located within the feeder stand 24, as it provides the necessary support and stability for the motor while also allowing for easy access and maintenance. During operation, the bowl feeder 4 rotates, utilizing centrifugal force and sweep arm 25 to guide 20 mm rounds into the slots of the feeder wheel 26. Rounds within the slots are discharged from the bowl to a transit slide 27 integrated with the bowl feeder stand 24. The transit slide 27 is custom-designed to sort and orient the rounds to ensure their tips point upwards at the outlet 28. The outlet 28 features a U-shape tailored to fit 20 mm rounds, preventing them from falling out. At the bottom of the outlet 28 is a tunnel 29 that is aligned with the starting location of a cup on the chain conveyor 6. During feeding, when the 20 mm round reaches the end of the outlet 28, it automatically drops into the cup through the tunnel 29. The design of the bowl feeder 4, including factors such as its size, shape, and orientation mechanisms, along with considerations like the bowl size, rotational speed, and the structure of the transit slide 27, ensures that the feeding rate precisely aligns with the speed of the chain conveyor 6. Additionally, a sensor 30 is installed at the outlet 28 to detect the presence or absence of 20 mm rounds without physical contact. This sensor, either a proximity or optical type, operates based on specific principles. In an embodiment, an inductive proximity sensor generates an electromagnetic field and detects disruptions caused by rounds. Alternatively, a photoelectric sensor emits a light beam and detects interruptions caused by rounds. When a 20 mm round enters the detection range of the sensor 30, it triggers the sensor to send a signal to the bowl feeder controller 31, indicating the presence of the 20 mm round. This signal enables synchronization with the chain conveyor 6. A gate 32 is integrated at the outlet 28 to regulate the feeding flow of 20 mm rounds. It opens to release ammunition and closes when a stop control signal is received. The bowl feeder controller 31 regulates the operation of the bowl feeder, receiving actuating signals from the control and management system 10 through communication unit 9. It controls functions such as starting and stopping the bowl feeder, adjusting feeding speed, controlling the gate, pausing in case of congestion detected by the vision system 8 stationed at the bowl feeder, or executing emergency stops when necessary.

FIG. 5 shows an embodiment of the exploded perspective view of the bowl feeder 4. Inside the bowl feeder, the clutch mechanism controls the rotation of the feeder bowl. A clutch cover 33 is used to protect the clutch mechanism by shielding the clutch from dust, debris, and other contaminants that could potentially affect its performance or cause damage. Additionally, it enhances safety of operators and maintenance personnel by preventing accidental contact with the moving parts of the clutch mechanism. A feeder wheel 26 and a friction clutch 34 is always attached. The feeder wheel 26 is responsible for transporting ammunition from the feeder bowl to the discharge assembly. It consists of a rotating disc with slots and grooves to accommodate and move the ammunition along its surface. The feeder wheel 26 ensures that 20 mm rounds are evenly distributed and oriented as they move towards the discharge assembly. The friction clutch 34 controls the rotation of the feeder wheel 26. It allows for the engagement and disengagement of the feeder wheel 26's rotation mechanism. When engaged, the clutch enables the rotation of the feeder wheel, allowing it to transport ammunition from the feeder bowl to the discharge assembly. When disengaged, the clutch interrupts the rotation of the feeder wheel 26, halting the feeding process. A sweep arm 25 is affixed to the feeder wheel 26, responsible for controlling the height of the ammunition as they traverse the wheel's surface. It ensures that properly oriented ammunition proceeds along the feeding track, while any misaligned or improperly positioned rounds are swept away. The feeder wheel 26 is mounted on a base plate 35, which incorporates shim 36, roller bearings 37, and blank assembly 38 for installing the discharge 39. The discharge 39 is dimensioned to accommodate the size of the 20 mm rounds and functions as the outlet through which ammunition is discharged from the bowl feeder to the downstream assembly.

In this embodiment of the 20 mm SPAM line, ammunition feeding flow proceeds in one direction. FIG. 6 shows an embodiment of the invention in a plan view. Within the loading area of the SPAM building, once 20 mm round bin 1 arrive and properly positioned, the robot 3 consistently retrieves bin 1, depositing ammunition into the bowl feeder 4 until bin 1 is emptied. The bin status is monitored by the vision system 8 stationed at the bowl feeder that communicates with the control and management system 10 via its communication unit 9. Control over the timing of each pickup and deposit lies with the control and management system 10, which sends commands to robot 3 via its communication unit 9. Subsequently, the bowl feeder 4 automatically aligns and releases 20 mm rounds onto the first cup 5 of the chain conveyor 6. Vision systems 8 stationed at the feeding area continuously monitor the status of the bowl feeder 4 and the chain conveyor 6, relaying updates such as misalignment alerts to the control and management system 10. In response, the system sends commands to the communication units 9 at the bowl feeder 4, and chain conveyor 6 to guide their activities. Additionally, the communication unit 9 at the SPAM 7 transmits SPAM status updates to the control and management system 10 for further action.

FIG. 7 illustrates an embodiment of a flowchart showing the operation of the SPAM autofeeding line in the present embodiment. At the beginning of the feeding process (step 100), 20 mm round bins 1 arrive at the loading area. The control and management system 10 transmits control signals to the robot 3, bowl feeder 4, and chain feed conveyor 6 to synchronize their status based on the set feed rate (step 101). Bins 1 are properly positioned for the robot 3 (step 102). Each bin is processed individually. Upon receiving start signal from the control and management system 10 (step 103), robot 3, bowl feeder 4, and chain feed conveyor 6 starts feeding 20 mm rounds into the SPAM (step 104). Periodically, as per a preset pickup frequency, the robot 3 retrieves a bin 1, empties its rounds into the bowl feeder 4, and then returns the bin 1. Meanwhile, the bowl feeder continues to feed 20 mm rounds to the chain conveyor 6. The vision system 8 stationed at the loading area checks if the bin 1 is empty (step 105). If affirmative, the empty bin 1 is either removed by the operator or by robot 3 if it is a mobile robot (step 106). In step 107, the vision system 8 at the loading area scans for any remaining bins. It confirms whether any bins are left in the loading area. If additional bins are present, the process returns to step 101. However, if no bins remain, the feeding process concludes when the bowl feeder 4 is empty, as reported by the vision system 8 stationed at the bowl feeder 4.

FIG. 8 illustrates an embodiment of a sequence diagram showing the communication and interactions between six components involved in the feeding process: control systems, including control and management system 10 and subcontrollers at robot 3, bowl feeder 4, chain conveyor 6, and vision systems 8. The process initiates with the control and management system 10 sending a control signal to activate the vision systems. Once activated, the vision systems respond with a “vision system ready” message. Subsequently, the control and management system 10 sends messages to robot 3, bowl feeder 4, and chain conveyor 6 to synchronize the feed rate, with each component confirming synchronization. Following this, parallel processes occur: the control and management system 10 sends control signals to robot 3, bowl feeder 4, and chain conveyor 6 to start feeding. Each component confirms readiness to start. Within a loop for all bins in the loading area, the control and management system 10 signals the vision system 8 stationed in the loading area to check the status of the current bin 1 to be picked up by the robot 3 to determine if it is empty. The vision system 8 reports the bin 1's status to the control and management system 10. If bin 1 is not empty, the control and management system 10 signals sorting robot 3 that bin 1 is ready. When it is time for robot 3 to feed the bowl feeder 4, it picks up bin 1, transfers the 20 mm rounds to bowl feeder 4, returns bin 1 to the loading area, and notifies the control and management system 10 that bin 1 has returned. Throughout the process, the control and management system 10 requests status updates from vision systems 8 stationed at different locations, and the vision systems 8 reply with the status. The loop continues until the vision system 8 at the loading area reports that no bins remain. Subsequently, the control and management system 10 sends messages/control signals to stop feeding and monitoring to robot 3, bowl feeder 4, chain conveyor 6, and vision systems 8, respectively.

FIG. 9 illustrates an embodiment of a flowchart showing the operation of the robot 3 during the feeding process. Upon receiving the control signal from the control and management system 10 to synchronize the feed rate (step 200), robot 3 aligns its feed rate with the other components in the feed system (step 201). Following this, upon receiving the control signal to begin feeding (step 202), robot 3 initiates the feeding process. It continuously monitors the preset pickup timer (step 203) to determine if it is time to pick up the bin 1 (step 204). If the pickup timer has not been reached, robot 3 remains in a waiting state until the designated pickup time (step 205). Once the pickup timer is reached, upon receiving the proceed signal from the control and management system 10 to proceed with the pickup (step 206), robot 3 scans the pickup location in the loading area to locate the bin 1 and calculates the optimal path for pickup (step 207). Subsequently, it activates the gripper mechanism in preparation for bin pickup (step 208). The robot arm then moves to the calculated position of the bin 1 for pickup according to the calculated path (step 209). Using the fork-shaped gripper, robot 3 securely grasps the bin 1 (step 210) and lifts it from its position in the loading area (step 211). The 20 mm rounds are then transferred from the bin 1 to the bowl feeder 4 for further processing (step 212). After one round of feeding, the robot arm returns to put down the bin (step 213) and notifies control and management system 10 that bin 1 has been returned. Robot 3 then awaits the next control signal to determine the subsequent action. Upon receipt of the next control signal from the control and management system 10 (step 214), robot 3 verifies the type of control signal received (step 215). If it's a feed signal, robot 3 returns to step 203 to prepare for the next bin pickup. If it's a stop signal, robot 3 completes its tasks and transitions to the rest position (step 216).

FIG. 10 illustrates an embodiment of a flowchart showing the operation of the bowl feeder 4 during the feeding process. Upon receiving the control signal from the control and management system 10 to synchronize the feed rate (step 300), bowl feeder 4 aligns its feed rate with the other components in the feed system (step 301). Upon receiving the control signal from the control and management system 10 to begin feeding (step 302), bowl feeder 4 starts the feeding process. It rotates to align the 20 mm rounds properly within the bowl feeder (step 303). Utilizing the vision system 8 stationed at the bowl feeder 4 and bowl feeder controls, it verifies that the 20 mm rounds are correctly aligned before discharge. Then, it releases the rounds onto the chain conveyor 6 one by one for further processing (step 304). A gate 32 at the outlet 28 regulates the feeding flow of 20 mm rounds based on the bowl feeder controller 31's control signals. Bowl feeder 4 continues feeding until a stop signal is received (step 305), at which point it stops operation (step 306).

FIG. 11 illustrates an embodiment of a flowchart showing the operation of the chain conveyor 6 during the feeding process. Upon receiving the control signal from the control and management system 10 to synchronize the feed rate (step 400), chain conveyor 6 aligns its feed rate with the other components in the feed system (step 401). Upon receiving the control signal from the control and management system 10 to begin feeding (step 402), chain conveyor 6 initiates the feeding process. It keeps running at a constant speed and receiving 20 mm rounds from the bowl feeder 4. Subsequently, the conveyor belt transports the rounds to SPAM for separation (step 403). Chain conveyor 6 continues operating until a stop signal is received (step 404), at which point it stops operation (step 405).

FIG. 12 illustrates an embodiment of a flowchart showing the operation of the control system during the feeding process. Firstly, the control and management system 10 initializes and prepares to start operation. It collects information, including status updates, from various vision systems 8 and subcontrollers at robot 3, bowl feeder 4, chain conveyor 6, and SPAM 7 (step 500). The received signals are processed to determine the appropriate action to take (step 501). Based on the processed signals, control and management system 10 generates control signals to actuate various components of the system (step 502). These control signals are then sent to the respective actuators, motors, and other devices to execute the desired actions (step 503). Throughout the entire feeding process, control and management system 10 continuously monitors the operation of the system to ensure it functions correctly and safely, leveraging the information received from the vision systems 8 (step 504). The system continues to run until instructed by the operator to stop (step 505), at which point it stops operation (step 506).

A person skilled in the art should understand that the embodiments of this invention may be provided as a method, a system, or a computer program product. These embodiments can take the form of software-only, hardware-only, or a combination of software and hardware implementations. The invention may utilize one or more computer programs, which are implemented in computer-readable memory and/or storage media containing executable program codes.
The embodiments of the invention are described with reference to block diagrams, flowcharts, and/or message sequence charts representing the method, system, and computer program product according to this application. It should be understood that computer program instructions may be used to implement each step and/or block in these flowcharts, block diagrams, and message sequence charts. These computer program codes and/or instructions can be implemented in computing devices, including general-purpose or dedicated computers, microprocessors, chips, or processors of any other programmable data processing device. The embodiments of the invention may be realized as program codes and/or instructions executable on a computer, processor, or any other programmable data processing device, creating an apparatus for implementing specific functions within one or more processors in the flowcharts, message sequence charts, and/or the blocks in the block diagrams.
The computer program instructions may be stored in a computer-readable memory, which can guide the computer or any other programmable data processing device to operate in a specific manner. These instructions stored in the computer-readable memory generate an artifact that includes an instruction apparatus. The instruction apparatus implements a specific function within one or more processes in the flowcharts, message sequence charts, and/or one or more blocks in the block diagrams.
The computer program instructions can be loaded onto a computer or another programmable data processing device. This allows a series of operations and steps to be performed, resulting in computer-implemented processing. The executed instructions on the computer or other programmable device provide steps for implementing a specific function within one or more processes in the flowcharts, message sequence charts, and/or one or more blocks in the block diagrams.
A person skilled in the art can make various modifications and variations to the embodiments of the invention without departing from the scope of this invention. This invention is intended to cover such modifications and variations, provided they fall within the protection defined by the following claims and their equivalent technologies.