The advancements in the design of the system have sparked the developments and implementation of different smart automated systems that that executes the duties of the respective jig systems but in a more convenient, reliable and easier manner. Some of the systems in jig industry have adopted the use of automated systems in their particular sectors such as the Parson automated driller which reduces the costs in various ways such as prolonging the life spans of the drill bits and also saving the number of hours needed in the drilling process. This automatic driller maintains a certain amount of weight on bit thereby taking full advantage of the rate of bit penetration while drilling.
Before the introduction of the person automatic driller, the drilling process did take longer hours and even the lifespan of the drilling bits themselves was reduced and shorter. The automated driller takes into account high level of accuracy and control due to the presence of controllers and actuators in the design device and hence acute level of accuracy in adjusting and taking intensive care of a specific weight on bit and consequently the rate of penetration of the bit is maximized (white 2001, p. 302). With the aid of a continuous feedback from hook load, with the target ring device acting as a sensor, rotary encoder located on rotation of drum draw works for reasons of attaining a high level of resolution measurement and the drilling fluid pressure, the brake handles of the drilling jig are triggered by the automatic driller.
A target that does not exceed the limits of specific weight on bit is placed for the purpose of drilling the rate of penetration and pressure resulting from the fluid (Hart 2007, p. 402). Weight is then added to the bit up to a certain amount where the best and desired rate of penetration and fluid pressure is achieved. It is cheaper and convenient to install the automated driller on a jig machine due to the presence of sensor that is already installed in electronic passion drilling machine. The advancement and execution of an automated silver drilling system ascertain to be of much importance and benefit as a method for drilling silver. The development will ensure the jig take the form of a horizontal or vertical drilling process and this will make it possible for construction of the depth of each drilling cycle to be correct and of a high level of precision.
The vertical or horizontal alignment form helps to drill straight and vast holes and also makes good use of drill press that is mounted on a tall floor. Also the automatic silver drilling system, we will be able to accommodate a variety of shapes of barrels such as the round, triangular and also the ones that are square in shape. With the work piece tightly fixed on the level table of the machine, the drill will be in consistent up and down movements making the bit to remain in a stable vertical position, and likewise for the horizontal position (Bucksch 2012, p. 124). Subsequently, the application of controllers in the design of the device will enable the person working on the machine or the operator to select the style of pen and also the appropriate depth of drill for each drilling cycle. The controllers will be of the high level of integration and more robust to the environmental conditions hence the automated silver drilling machine will be able to operate in any condition.
Moreover, the reliance on this automated system will be able to detect when a barrel is aligned in an incorrect manner, or it is missing and thus the application of a halt process to prevent any damage that may arise. This, in turn, will help to improve the efficiency of the energy as well as increasing the accuracy of the machine. Also, the life span will also be increased. The automated silver drilling machine will be fitted with smart sensors that are not only more consistent and very reliable but also of high accuracy regarding data collection (Dacey 2013, p. 123). The smart sensors will give extensive information on various parameters such as the strain, position, and pressure.
Nevertheless the advancement and development of this automated silver drilling machine system will ensure the barrel is held on axis with the drill and is not only secure so as to prevent the pen from changing its position but at the same time do this without use of excess force which may result in marking or the deformation the soft silver of the pen .the orientation of the assembly of ball pen device will be in such a way that it in cooperates all the security and also taking into consideration the productivity and use of little energy or strain.
In general, the advancement and implementation of the silver drill jig will not only prove to be of very much use to human but also take in productivity standards and the safety measures within the drilling industry.
In this section, the overall working mechanism of the automated silver drilling machine is described. It includes the architecture of the device and its development.
Before coming up with the design of the device, there are some factors that were put into consideration first. They include
- The reduction of idle time –once the time that the jig machine takes when not performing any operation is reduced, there will be a reduction in the cost used in production and increased efficiency. The employed sensors will automatically detect whenever there is no operation that is going on and send signals to the programmable control systems which will, in turn, take the necessary action.
- The positioning of the clamp- clamps hold the work piece strongly thereby keeping it fully in contact with the locators during the working of the automated silver drilling machine(Bhatkar 2005, p. 234). The clamping should be strong enough such that the deflections in the jig are minimized as possible but at the same time, it should not destroy the work piece. This is done by ensuring that pressure is equally distributed all over the work piece. For the automated silver drilling machine, there is no need for fixing the clamp with soft materials such as fiber. Also, it should be detached with least amount of effort.
- The neatness of the work piece – the work piece should be as neat as possible so that the drills will be of high quality. This will be ensured by the application of the pneumatic motor actuator that contains compressed air for the removal of the chips.
- The setting up of the reduction time- the loading and offloading should be set such that they take the minimum amount of time possible. In the automated silver drilling machine, the controllers will help in achieving this
- Proper location of the elements – the positioning of the various elements in the work piece should be accurate with regards to the tools that guide the jig. They should be correctly set so that the drills are accurately made in the work piece(Fewster 2006, p. 324). The most common type used of the locating device is the pin. In the automated silver drilling system there will be no need to replace the pins when locating work piece that is having a varying dimension because the system will be able to automatically locate any dimension whether it is constant or varying, this will be achieved by the assistance of programmable controller system and actuator system.
- Standardization-the silver drill system should obey the safety standards and the other standards such as measurements i.e. it should provide the control of all the six degrees of freedom; the linear and rotational degrees in space(Hillary 2006, p. 320). It should be free to move along the three axes and to achieve all these; the surface location should be properly located by the use of controllers.
- Safety of the working place -the safeties will be increased since the machine will be automatically operated and in the case of any anomalous behavior, the sensors will sense and send the information to the controllers for effective action.
Once all these factors have been factored, there production will be of high precision, reliability, efficiency and also the rate of production will be increased
The device will be required to go through very few operations since the process has been automated. Once the operation has started, it is the smart jig that will take control everything .it is a smart jig because it is fitted with various sensors, controllers, and actuators that will enhance the automation process. Below are the outlined various steps of how the automated silver drilling machine will operate to produce very many drills that are of quality at a faster rate.
Construction of the device
The stepper motor acts as the principal part of the automated silver drilling machine coupled with the programmable logic controller .the drilling machine is fixed on the press that is connected using nuts and bolts. The structure contains a barrel which is having its one end closed and the other remaining end tapered. The movement of lead screw through the threaded nut provides for tapering. One end of the lead screw is located in the barrel whereas the other one is situated in the stepper motor. The stepper motor acts as an actuator and is firmly fixed on the automated silver drilling machine. There are two rollers that slide in channels within the structure which enable the drill machine to move in any direction, for example, the forward direction and reverse direction. At the bottom of the jig machine, a fixture is attached through the use of bolts hence holding it firmly and in a stable position during the operation (Bucksch 2012, p. 332). Moreover the power is supplied to the machine for purposes of driving the machine operation. The circuit is also powered.
Principle of operation
The drilling operation is done with the assistance of movement of power screw. The power screw also called the lead screw is monitored by the actuator motor stepper which has been coupled to it .the keypad that is located in the circuit gives the command to the stepper motor .upon taking the command, the motor rotates thereby rotating the power screw in turn. The power screw then converts the spinning movement of the shaft in both the reverse and forward direction. In the barrel structure, there are two rollers which slide on two channels and hence enabling easy movement of the drilling machine .at the bottom of the drill machine; there is a firm contact that is provided by the fixture (James 2004, p. 412). There are two ways in which this drilling machine works, though our main concern is the automatic mode
In this mode, the keypad gives instructions to the drill machine .the keypad contains two push button which helps to control the movement of the drilling machine, and the rate of feed of the machine .another push button gives the machine instruction to move in the reverse direction hence the button is pressed only once. The jig thus automatically comes to a commencing position. On the other hand, there is one button that controls the tool that is used for drilling
Automatic mode of operation
Here the data of the operation that needs to be performed is fed into the machine by setting the parameters such as the depth of the drill, the number of jobs that needs to be relayed between the two operations. The machine then performs the whole remaining operation automatically as long as the data have been fed. For instance, there are 400 jobs that require requiring to be operated on, and the depth of the drill is 8 millimeter, the height of pens is to be 40 millimeters, and then a delay period has been fed of an interval of 20 seconds. The machine will automatically undertake the operation.
From here, and with the help of controllers such as the EZMotion card controller within the programmable logic controller, the blade is raised up, and the cutting process begins. The controllers help to achieve production of pens that are all the same in terms of their sizes .this will take a few seconds and the process repeats itself thereby producing a mass number of drills. The holes also can be drilled to proper size from one side and then precisely tapered on a thread on the other end. The drill head is designed in such a way that a shuttle mechanism is applied where the parts are moved from one step and sent while filling an additional part into the position for the initial step (Perterson 2014, p. 352). The designing of chip removal is in cooperated in the process by the aid of pneumatic actuator.
For vertical drilling machines, the drill will be fixed firmly on a vertical spindle and the work piece held on the drilling machine. The axes of the drill and the hole to be drilled are automatically aligned by the aid of a programmable logic controller which will consequently aid in the automation of the whole operation. Below is the block diagram of the drilling system and a functional diagram respectively.
Thus in order to automate the pen, it will undergo five phases, i.e. loading station, point filling station, the ink charging phase, the gas charging and plug fitting station, and finally the cap insertion and sealing station.
Phase1; loading station
Once the machine has been automated, it is loaded with a cartridge, the cartridge is coming from the vibrating bowl and it is positioned into the fixture with the correct alignment. This is aided by the use of a cartridge Hooper machine (James 2003, p. 125). The cartridges are placed at the top of the Hooper machine, and they will drop to the bottom part. In order to prevent any deadlock in the hopper machine, its two sides will hope down and up at an interval of two seconds. The vibration bars at the center of the hopper machine vibrates making the cartridges to drop one after the other. After these the cartridges are loaded into the conveyor, where they fall into the conveyor slots. The conveyor then takes the pen cartridge to the air rotation arm where they are placed into a fixture. The air rotation then rotates the arm to the front down (here the arm of the clamp moves down to the conveyor and clips a cartridge) to the front where air rotation takes the arm to the fixture thereby the pen is clipped by the fixture and the arm gets pulled back. Below is the hopper machine
Phase 2; Point filling station
In this stage, the points that are coming from the vibration bowl are taken and fixed onto the cartridge. For better holding of the cartridge, a special fixture is used. This fixture is designed in such a manner that it will be able to move both in the forward direction and reverse direction along the assembly line with a high velocity and at the same time, the fixture should be able to make the cartridge rotate by 180 degrees for purposes of filling the ink immediately the point is attached to the cartridge. A vibration bowl is used for supplying the plugs into the conveyor which transports them to the gripper.
Phase 3; ink charging station
This is the phase where the ink is being filled. The ink is filled into the cartridge. This is done by sliding a horizontal slider to make the nozzle touch the surfaces of reference thus the cartridge axis gets aligned with the axis of the nozzle. Ink is then spread into cartridge slide walls to eliminate splashing (Kok Kiong Tan 2006, p. 425). A programmable logic circuit helps to control the ink flow to the cartridge.
Phase 4; gas charging and plug fitting station
At this stage, the air is charged into the cartridge and then it is tightly closed with the help of a plug. The reason for this is to obtain a pressure inside the pen. All these are done at the same time. Otherwise the gas may diffuse into the atmosphere.
Phase 5; insertion of cap and sealing station
This is the last stage where the cap is inserted and fitted into position, after which it is sealed. The caps which are coming from the vibrating bowl are conveyed near to the assembly line by a rail. The rail line is designed in such a way that it allows for one cap at a time. Once the cap is allowed, it touches the stopper making a gripper arm to pick it and place it on a cartridge. The gripper is operated by an actuator that enables it to move both vertically and in horizontal direction. When it moves horizontally, it places the cap on a cartridge and when it moves vertically, it places the cap to the assembly line. After the cartridge is capped, it has to be sealed using an ultrasonic welding unit as shown below
Flow chart diagram
The quality inspection was computer vision in order to certain that the pens produced are of high quality.
The device will have the following advantages
1.There will be increased efficiency in the production of the silver pens which will be of different variety regarding shape and sizes
2.The design will allow for the drilling of unsymmetrical shapes hence will accommodate all kinds of job
3.The time required for the operation of the machine is reduced since it will be able to perform many duties in a shorter period. It is improved, and increased safety of the operator since most of the duty will be carried out by the automated machine (Marie 2013, p. 453).
4.Since the device will contain the various communication system; sensors, controllers and actuators, the life span of the machine will be increased since these communication systems will together to ensure that whenever there is a fault somewhere, it is rectified inappropriate time.
5.The maintenance of the machine will also be minimal since most of the operation will be automatic.
6.Moreover, the operation of the machine does not requires skilled labor hence even semi-skilled workers can operate the device thereby reducing the labor costs.
7.The rate of production will be increased and quality also. This is because the time taken in the production will be very minimal.
Since the operation will be automated, the will be no need for measuring the distances or positions. This, therefore, makes the machine to be quicker (Mathew 2005, p. 234).
Details of the proposal
Various factors were considered and adopted to realize the objective of automated silver drill System. The system will get controlled with the aid of a programmable logic controller. The below block diagram demonstrates how the communication systems have been used together in order to attain the best outcome from the design of the device .information gathered from all the sensors in the form of data are fed into the integrated programmable logic controller that in turn analyses the data and take an action of providing appropriate control of the device. From the controller, it is then conveyed to the actuators that are eternally attached to the smart jig. Below is a diagram of how these communication systems are integrated
Systems element technical research
These are communication systems that work together with other communication systems such as the controllers and actuators. The sensors collect information in a system and send signals to the controllers which in turn take action (Jack 2011, p. 471). Most sensors are located within the machine. Extensive research was done before selecting the kind of sensors to be used for the control system. Several factors such as the vibrations, taking of measurements, changes in surface conditions, the alignment of holes and distance among others determined the kind of sensors to be used for the designing of automated silver drill system. With regards to the accurate and consistent alignment of the holes, it was required that, the API laser trackers. Also for detection of marks, sensing of changes in the surface conditions and detection of parts, the photoelectric sensor was used. In the case of the vibrations of the machine, an IL series laser sensor was selected. The touch probe sensors were also used. below are the pictures of how the sensors that have applied look like.
The control system for automated silver drill system could either be achieved with the help of programmable logic controller .the programmable logic controller can control very many programmers at a simultaneously or at the same time. The EZ Motion provides a continuous motion through the assistance of its internal processor thereby giving one and half times precise motion that is synchronized to the reference encoder (Paul 2007, p. 421). This unit drive come along with safety rules and does not need to be constantly powered on and off thereby saving energy the robot has three outputs which translate to eight binary codes. These binary codes cover the rotation of the automatic silver drilling machined thus controlling the stop and run.
These are normally located outside the machine. They receive signals from the programmable logic controllers and take an action of controlling the mechanism of a system. They convert the signals received in the form of electrical energy into mechanical energy. They include the steeper motor, the dc servo motor, brushless motor among others. Actuators are motors that that will be applied for purposes of controlling the working mechanisms of the automated silver drilling system. There are some motors, and each has its limitations and advantages thus you must choose to employ motors that have best advantages so as to give you good results.
The stepper motor cannot be driven directly with the help of controller pins. This is because the controller cannot deliver the amount of current that is required to drive the motor, and it will result to back emf within the circuit while rotating. This may destroy the controller. Hence a drive circuit is used in the case of high efficiency that is associated with reduced noise and fewer sparks, the brushless dc servo motor was chosen over the one that is brushed. It is a stepper motor that rotates small specific steps and contains a comprehensive compatibility of both digital and analogue feedback signals. This is more reliable and also eliminates cases of electromagnetic interference than the brushed motor (Owens 2000, p. 411).
Nevertheless, when it comes to the control of chips, it was appropriate to choose a pneumatic motor that contains compressed air which is powered to get rid of the chips without any inconveniences such as scattering the working area. When the chips are continuous, most of them will jumble between the work piece and the bushing hence the pneumatic motors helps to eliminate this without any difficulty. Also the dc, servo motor was chosen over the dc motor. This is due to the fact the dc motors are in continuous rotation mode until power is removed from them. This implies that a lot of energy may be wasted during the process hence reduction in the efficiency. Therefore the dc servo motors that comprise a position sensor, a gearing set control circuits and a position sensor was chosen hence the positioning of the blade will be easily controlled.
Selections of device components
Below are the various devices that were selected and their descriptions
Stepper motor –SBL1360
A stepper motor is a servo motor that does not have brushes and attenuates the full rotation of a motor into an equal number of steps. It was chosen for its ability to be reliable produce a, highly efficient and will, therefore, control the machine for best operations. It is first connected to the driver circuit to prevent any damage to the motor. Below is a 3D diagram for the motor
The power or the lead screw help in controlling the motion of the machine by translating the turning motion of the machine to a linear motion. They are easily adaptable and hence provide higher performance.
Programmable logic controller-RIO-4720X
Programmable logic controller is a computer based system that continually monitors the input device into a system and subsequently performs logic operations. Almost all the automated machines have the programmable logic controller due to its robust characteristics. It consists of a processor core, peripheral that are programmed and a memory. It will continually monitor and take action whenever there is a problem within the system. In order to run and process information to the actuators, the controller should have a large memory. Also it should have various ports as inputs and outputs for the purposes of coordination with the sensors. Hence the controller that was chosen was RIO-4720X as shown in the figure below. The programmable logic controller will actually act as the controller of all the parts as it acts as the memory / the brain (poulos 2013, p. 524).
Current sensor –ACS712
The relay system consists of a switch which is operating on a small current but can control a larger amount of electric current. For automated silver drilling machine, it is located within the circuit of the programmable logic controller.it is thus connected with a current sensor that automatically detects when a large amount of current is flowing through the system and the sends signals for correction. in order to perform these, a spark fun hall effect current sensor breakout-ACS712 was used. It is able to sense both ac and dc currents and produce a good output
Piezoelectric sensor-HIFU piezo, 7MHz
Since there is a need to measure the changes in acceleration, strain, force and pressure, a piezoelectric sensor as used? The type chosen was HIFU 7MHz due to its ability to convert electrical energy into very high mechanical vibrations
This was selected due to its ability to monitor the position of the shaft that is rotating and thereby giving feedbacks elements in a closed loop system of control. It also has a high frequency and resolution.
Vibration sensor/accelerometer-EAR99 (Also known as accelerometers).
These were selected due to their ability to sense and monitoring of vibration in rotating machines. The EAR99 was selected due to its ability to operate at both extreme temperatures i.e very high and very low temperatures below is a 3D of how they look
The ability of the devices to attain the main objectives of the device that includes high precision and increased efficiency was considered mostly rather than the cost that is associated with them. To ensure that the soft silver plate is not damaged and that they are all of the same sizes that will result in best the productivity, the material components definitely will be quite expensive (Pessen 2013, p. 364). Thus for the workability and benefit of this design, the cost of the components and materials was approximated as shown below.
The units for the costs are in pounds
- Power screw £1500
- Programmable logic controller £2500
- Relay electronic £100
- Keypad £70
- LCD electronic £ 100
- Power adapters £ 500
- Coupling devices £100
- Slide rollers £250
- Stepper motors £400
The principal objective of this project was to give a detailed and very comprehensive design of automated silver drill machine for a pen. The expectation of the automated smart system was to make it possible for holes to be automatically drilled in a silver drilling system with the aid of diverse communication systems such as the controller, sensors, and actuators. A long drill that extends the length of the barrel and is required to produce a two stage hole i.e. a clearance for the refill cartridge for a ball pen and a clearance for the tip of the refill cartridge .this in turn helps to form a tapered form at the end of the barrel of a silver pencil or pen (Perterson 2014, p. 524).
These communication systems; actuators, controllers and sensors all work in an inclusive and concurrent manner whereby each communication system sends information to each other so that whenever there is unusual eventuality the system will be able to define and examine and lastly take action based on the collected and available data in a precise and accommodative manner. The controller that has been selected for the design of this system is a programmable logic controller since it can operate many tasks at the same time.The sensors make it possible for the automated silver drill machine to detect when a barrel is aligned in an incorrect manner, or it is missing and thus the application of a halt process in order not to cause any damage thus improving the efficiency of the energy as well as increasing the accuracy of the machine.
The actuator that has been preferred is the stepper motor thus aiding to activate and deactivate the system in cases of detection of abnormality. Thus there are many benefits that come along with the use of automated silver drilling machine. They may include a reduction in accidents since the safety of the working environment will be improved. Increased level of precision and accuracy of the drills produced. Also, the need for regular inspection and control expenses will be reduced since most of the controls and checking of the machine will be automated. Also, the quality of the manufactured products will be consistent thus such that there will be no variations in the dimensions of drills produced. Also, the production will be increased since it takes a shorter time to produce a large number of drills. Above all, the cost of manpower will be highly reduced since even semi-skilled operators can use them without difficulty (pius 2009, p. 245).
In conclusion, therefore from the detailed information particulars of the design, the device system verified that the application of various communication systems such as the sensors, controllers, and actuators could help to achieve the objective of this device and in turn increasing the speed, productivity, reliability, and safety within the drilling industry. On the other hand, the design gave emphasis on some limitations related to the implementation advancement of the device or gadget. For instance, a gadget designed to depend on ……..sensor may experience some challenges posed by interferences such as change of weather conditions or radiations from infrared rays.
Recommendation for future research
The above report has intricately described the design and overall concept including the architect of the automated silver drill jig system. Thus what needs to be done is coming up with the model or a prototype of the device. The prototype will help in testing the workability of the project and some changes for further refining of the design. The results and inferences obtained from the testability of the prototype of the automated silver drill jig system show a representation of the actual gadget (Racheal 2005, p. 421). Hence, it is appropriate if an action is taken for the coming. up with the model so that it can be tested and further suitable changes are incorporated if in case there is.
Bamber, JL 2012, Mass Balance of the Cryosphere, 3rd edn, Springer-Verlag, Liverpool.
Bhatkar, DVP 2005, Distributed Computer Control Systems in Industrial Automation, 1st edn, CRC Press, manchester.
Bucksch, H 2012, Dictionary Geotechnical Engineering / Wörterbuch GeoTechnik, 2nd edn, Springer-Verlag, Hull.
Dacey, PW 2013, Flue Gas Desulphurisation: System Performance, 3rd edn, IEA Coal Research, Manchester.
Fewster, G 2006, Experiences of Test Automation, 2nd edn, Addison-Wesley Professional, Leicester.
Hart, S 2007, Automation: The Impact of Technological Change, 3rd edn, American Enterprise Institute for Public Policy Research, Manchester.
Herbert, A 2002, Canadian Machinery and Metalworking, 3rd edn, MacLean-Hunter Publishing Company, london.
Hillary, B 2006, Automated Manufacturing, 1st edn, ASTM International, London.
Jack, A 2011, Automation of design, analysis, and manufacturing, 2nd edn, Springer-Verlag, Liverpool.
james, K 2000, Automation, 2nd edn, Penton Publishing Company, Leicester.
James, W 2003, British Machinist & Automated Manufacturing, 2nd edn, McGraw-Hill, Stoke.
James, P 2003, Energy policy and land-use planning: an international perspective, 4th edn, Pergamon Press, London.
James, L 2004, New Optimization Techniques in Engineering, 1st edn, Springer, London.
Kok Kiong Tan, ASP 2006, Drives and Control for Industrial Automation, 2nd edn, Springer Science & Business Media, london.
Lawrance, C 2010, Sensors and Actuators: Engineering System Instrumentation, 2nd edn, CRC Press, LIverpool.
Marie, F 2013, Industrial Automation, 1st edn, McGraw Hill Professional, London.
Marthar, D 2003, Official Gazette of the Patent and Trademark Office, 2nd edn, Department of Commerce, Patent and Trademark Office, london.
Mathew, P 2005, Dead Simple, 4th edn, Carroll & Graf, London.
Mstaffer, C 2004, Machinery and Production Engineering, 2nd edn, Machinery Publishing Company, SToke.
Owens, SE 2000, Land use planning policy and climate change, 2nd edn, HMSO, Stoke.
Paul, B 2007, Automated Manufacturing Systems: Actuators, Controls, Sensors, and Robotics, 2nd edn, Glencoe, Hull.
Perterson 2014, Machinery, 4th edn, New word press, Leicester.
Pessen, DW 2013, Industrial Automation, 3rd edn, John Wiley & Sons, liverpool.
peter, B 2009, Automation and industrial workers, 2nd edn, Pergamon Press, Liverpool.
Peterson, P 2014, The Gun Digest Book of Modern Gun Values, 3rd edn, Gun Digest Books, London.
pius, R 2009, Piezoelectric Actuators: Control Applications of Smart Materials, 3rd edn, CRC Press, Stoke.
poulos, P 2013, Natural Hazards: State-of-the-Art at the End of the Second Millennium, 5th edn, Springer Science & Business Medi, Hull.
Racheal 2005, Mine Planning and Equipment Selection, 2nd edn, CRC Press, Stoke.
Richard, M 2009, Handbook Of Industrial Automation, 3rd edn, CRC Press, London.
Son, R 2002, Machinery, Volume 69, 3rd edn, Industrial Press, london.
thomas, R 2011, Thomas Register of American Manufacturers, 1st edn, Thomas Publishing Company, london.
Tsuchiya, Y 2011, Tsunami: Progress in Prediction, Disaster Prevention and Warning, 3rd edn, Springer, London.
Visconti, G 2011, Global Change and Protected Areas, 4th edn, Springer, Leicester.
white, J 2001, Assembly Automation and Product Design, 2nd edn, CRC Press, Hull.
Yabushita, S 2013, Dynamics of Comets and Asteroids and Their Role in Earth History:, 1st edn, Springer Science & Business Media, Stoke.