An airbag system for protecting rear seat occupants in dynamic side impacts using an improved packaging arrangement is provided. The system includes seat base and seat back frames. The seat back frame is movable between an upright position and a reclined position. The system further includes a unified airbag having a pelvic portion and a thoracic portion. The pelvic portion is positioned adjacent to the seat base frame. The thoracic portion is positioned adjacent to the seat back frame. The unified airbag is attached to the seat base frame by fixed anchors and to the seat back frame by a movable anchor. A grooved track is provided for attachment of the movable anchor. The airbag may be a strip shape or a triangular shape. One or more tethers may be attached to the unified airbag.

Interior panels having integrated airbag doors for motor vehicles and methods for making such interior panels are provided herein. In one example, an interior panel comprises a substrate having outer and inner surfaces and an opening extending therethrough. A multi-shot injection molded airbag chute-door assembly is mounted to the substrate and comprises a chute wall that at least partially surrounds an interior space. A door flap portion is pivotally connected to the chute wall and at least partially covers the opening. A perimeter flange extends from the chute wall and has a flange section that overlies the outer surface of the substrate. A molded-in lip feature extends from the flange section and contacts the outer surface to form a seal between the flange section and the substrate. A skin covering extends over the substrate and a foam is disposed between the skin covering and the substrate.

Aspirator for an airbag deploying into a vehicle passenger compartment in order to protect a driver of the vehicle during an accident, includes a housing having an innermost and an outermost wall and defining an outlet at a distal end leading to an airbag and coaxial flow passages between the innermost and outermost walls into which air from a passenger compartment flows to inflate the airbag. An aspiration system is coupled to the housing and configured to direct gas into the flow passages to mix with the air from the passenger compartment in the flow passages. The aspiration system includes openings on an inner side of the outermost wall and on an outer side of the innermost wall. These openings are configured such that the gas is directed therefrom into the flow passages in a direction substantially parallel to a flow direction of air into the flow passages.

The present invention relates to a trolley, and more particularly to a lifting trolley capable of raising and lowering goods. The lifting trolley includes a trolley frame, a drive mechanism, and a bearing mechanism. The bearing mechanism is vertically slidably connected to the trolley frame, and the drive mechanism is disposed on the trolley frame and drives the bearing mechanism to slide vertically. Compared with the prior art, the lifting trolley provided by the present invention saves time and effort, is accurate in positioning, and facilitates conveying of goods.

Construction is achieved that is capable of maintaining the holding force by which a support bracket 12a holds an outer column 13a. One pivoting friction plate 25 for telescopic mechanism is held between the inside surface of a support plate section 20a of the support bracket 12a and the outside surface of a displacement bracket 18a that is fastened to the outer column 13a. When adjusting the forward-backward position of a steering wheel, the pivoting friction plate 25 for telescopic mechanism pivots around a support pin 33 as an adjustment rod 22a displaces along a long hole 19a for telescopic mechanism and a long guide hole 32.

Airbag inflator system includes an inflatable airbag, e.g., a side curtain airbag, a housing, a gas generating system arranged apart from the housing for generating gas, and a conduit leading from the gas generating system to the housing to provide gas to the housing, e.g., to a lateral end of the housing. A filter may be arranged between the gas generating system and the housing, possibly in the conduit. A nozzle may be arranged between the gas generating system and an interior of the airbag, which nozzle is varied as a function of temperature. The housing may be movably arranged relative to a fixed base and mounted to vary its relation to the base as a function of temperature, e.g., via elastic or deformable supports which support the housing on the base.

A lightweight folding motorized chair with mechanical traction steering and braking. A folding frame supports the traction wheels and the drive system with hinged frame members configured to mechanically fold the control levers, wheels and periphery components into a substantially flat configuration for easy storage in small spaces. A mix of weight saving choices including: structural materials; mechanical traction control system; lithium ion battery; and overall lightweight design keeps the folding motorized chair at a size and weight that a person can lift into the trunk of a car.

A luggage case may include opposing sidewalls forming minor faces, opposing sidewalls forming major faces, and opposing end walls together forming an article defining an enclosed space. A line of separation may be formed in said minor faces and end walls. A first portion of the line of separation may extend along a first portion of opposing minor faces at a location proximate one of said opposing major faces and corresponding one of said opposing end walls positioned therebetween. A second portion of the line of separation may extend along a second portion of said opposing minor faces in a direction away from said one of said opposing major faces and towards other of said opposing major faces.

A luggage case (100, 600, 700, 800, 900) may include opposing sidewalls forming minor faces (105, 106), opposing sidewalls forming major faces (101, 102), and opposing end walls (103, 104) together forming an article defining an enclosed space (109). A line of separation (150) may be formed in said minor faces (105, 160) and end walls (103, 104). A first portion of the line of separation (150) may extend along a first portion of opposing minor faces (105, 106) at a location proximate one of said opposing major faces (101, 102) and corresponding one of said opposing end walls (103, 104) positioned therebetween. A second portion of the line of separation (150) may extend along a second portion of said opposing minor faces (105, 106) in a direction away from said one of said opposing major faces (101, 102) and towards other of said opposing major faces (101, 102).

A pre-weakened cover of an airbag module is provided including a layer having an outer show surface and an opposing inner surface. A plurality of first cuts is arranged at a first angle on the inner surface. A plurality of second cuts is arranged at a second angle on the inner surface. Each of the second cuts intersects two adjacent first cuts to form a generally V-shaped pattern.

A pre-weakened cover of an airbag module is provided including a layer having an outer show surface and an opposing inner surface. A plurality of first cuts is arranged at a first angle on the inner surface. A plurality of second cuts is arranged at a second angle on the inner surface. Each of the second cuts intersects two adjacent first cuts to form a generally V-shaped pattern.

A cutting tool cutting tool may include a tool body having a plurality of blades extending radially therefrom; and a plurality of rotatable cutting elements mounted on at least one of the plurality of blades, wherein the plurality of rotatable cutting elements are mounted on the at least one blade in a nose and/or shoulder region of the cutting tool at a side rake angle ranging from about 10 to about 30 degrees or −10 to about −30 degrees.

A tubular string is advanced with a bottom hole assembly as the hole is drilled and reamed in a desired direction with the aid of directional drilling equipment adjacent the bit. When the advanced tubular forms the desired lap to the existing tubular, the assembly can be configured to cement the tubular and expansion can then be accomplished to fill the annular space and enhance the cement bonding. The expansion equipment can create a bottom bell on the expanded tubular and expand the top end into a bell of the existing tubular so that a monobore is created as the process is repeated with each added string. Numerous variations are contemplated for each single trip including but not limited to the direction of expansion, whether cementing or expansion occurs first, reforming folded tubing in the hole as well as the nature of the expansion tool and pressure control when drilling.

A drilling apparatus for drilling boreholes in an underground formation includes a tool body that can be positioned in a borehole where drilling is to take place. The apparatus further includes a gas cutting torch having a nozzle, a supply of a cutting gas connected to the gas cutting torch. In some embodiments, the gas cutting torch and supply of cutting gas may be connected by an umbilical link. The tool body may be advanced through the borehole as drilling takes place. In some embodiments, the tool body may be advanced via a tractor device that forms part of the tool body or attached to the tool body.

Methods and systems are described for improved drilling operations through the use of real-time drilling data to predict bit wear, lithology, pore pressure, a rotating friction coefficient, permeability, and cost in real-time and to adjust drilling parameters in real-time based on the predictions. The real-time lithology prediction is made by processing the real-time drilling data through a multilayer neural network. The real-time bit wear prediction is made by using the real-time drilling data to predict a bit efficiency factor and to detect changes in the bit efficiency factor over time. These predictions may be used to adjust drilling parameters in the drilling operation in real-time, subject to override by the operator. The methods and systems may also include determining various downhole hydraulics parameters and a rotary friction factor. Historical data may be used in combination with real-time data to provide expert system assistance and to identify safety concerns.

An attitude hold controller method includes receiving at a navigable apparatus a demand inclination and a demand azimuth with respect to a global coordinate system and determining at the navigable apparatus a demand attitude vector according to the received demand inclination and the demand azimuth. Determining at the navigable apparatus a current navigable apparatus attitude vector. Evaluating a control law using the current navigable apparatus vector and the navigable apparatus demand attitude to derive a control law tool face, converting the control law tool face to an equivalent tool face, and applying the equivalent tool face with the navigable apparatus to control the navigable apparatus attitude.

The invention relates to a method and apparatus for opening threaded joints of drilling equipment (6) by striking the drilling equipment (6) with the percussion device of a rock drilling rig (1) and by measuring vibration originating from the drilling equipment (6) during striking. In addition to vibration, measuring means (9) measure a parameter defining at least one additional condition, on the basis of which the decision to stop striking is made.

Described herein is a wear indicator (100) for use in a drill bit or a core head. The wear indicator (100) comprises an elongate element that forms part of the drill bit. The elongate element has a plurality of numbers (110, 120, 130, 140, 150, 160, 170, 180) formed along its length, each number (110, 120, 130, 140, 150, 160, 170, 180) being formed as a void and corresponds to a level of wear in accordance with the IADC dull grading system. As the drill becomes worn, the wear indicator (100) wears at the same rate to reveal one of the numbers (110, 120, 130, 140, 150, 160, 170, 180). The numbers range from “1” to “8” where the number “1” illustrates the least wear and the number “8” indicates the most wear. When unworn, none of the numbers are visible.

A drill bit assembly for measuring reservoir formation properties comprises a bit head and a pin body, and an electrically insulated gap joint between two conductive parts of the drill bit assembly. The bit head has a cutting end and an opposite connecting end with an engagement section. The pin body comprises a connecting end with an engagement section. The pin connecting end is connected to the bit head connecting end such that the engagement sections overlap. The electrically insulating gap joint can fill a gap between the bit head and pin body engagement sections such that the bit head and pin body are mechanically connected together at the connecting ends but electrically separated. Alternatively or additionally, the pin body can have two pieces which are separated by an electrically insulating gap joint. An electrical conductor is electrically connected at a first end to the bit head and is communicable at a second end with an alternating current signal to transmit an alternating current into the bit head, thereby inducing an electric current into a reservoir formation adjacent the bit head. Electronic equipment includes measurement circuitry configured to determine the alternating current at the bit head, the alternating current being inversely proportional to a bit resistivity of the formation.

In some example embodiments, a system includes a drill string having a drill bit. The drill string extends through at least part of a well bore. The system also includes a first vibrational sensor, positioned on the drill bit to measure, at a first location on the drill string, an amplitude of one or more of an axial vibration and a lateral vibration. The system also includes a second vibrational sensor, positioned above the drill bit and on the drill string. The second vibration sensor is to measure, at a second location on the drill string, one or more of an axial vibration and a lateral vibration. The system includes a processor unit to determine a type of vibration based on a comparison of the amplitude at the first location to the amplitude at the second location, wherein the type of vibration is at least one of bit whirl of the drill bit and a while of a bottom hole assembly that is part of the drill string.

In one aspect, an apparatus for drilling a wellbore into an earth formation is disclosed, which apparatus, according to one embodiment, may include a drill string configured to be conveyed into a wellbore, wherein an annulus is formed between the drill string and a wellbore wall, a first flow device configured to circulate a first fluid from an annulus to a bore of the drill string, and a second flow device positioned downhole of the first flow device, the second flow device configured to circulate a second fluid from the bore of the drill string to the annulus.

According to an embodiment, a drilling fluid comprises: water and a set accelerator, wherein the drilling fluid has a 10 minute gel strength of less than 20 lb*ft/100 sq ft, wherein the drilling fluid has a density in the range of about 9 to about 14 pounds per gallon, wherein the drilling fluid remains pourable for at least 5 days, and wherein when at least one part of the drilling fluid mixes with three parts of a cement composition consisting of water and cement, the drilling fluid cement composition mixture develops a compressive strength of at least 1,200 psi. According to another embodiment, a method of using the drilling fluid comprises the steps of: introducing the drilling fluid into at least a portion of a subterranean formation, wherein at least a portion of the drilling fluid is capable of mixing with a cement composition.

Diamond bonded constructions comprise a diamond body attached to a substrate, wherein the body includes a first diamond bonded volume, and a second diamond bonded volume attached thereto. The second volume may be provided in the form of a powder or a presintered mass prior to attachment, and the first volume may be provided in the form of presintered pieces when combined with the second volume. The first volume diamond volume content is greater than about 94 percent, and is the same or greater than that of the second volume. The first volume is sintered during a first HPHT process, and the second volume is sintered and/or attached to the first volume during a second HPHT process. The first HPHT pressure is greater than the second HPHT pressure. The substrate is not an infiltration substrate used to form the first diamond volume. The diamond body may be thermally stable.

A cutting element for an earth-boring tool. The cutting element comprises a substrate base, and a volume of polycrystalline diamond material on an end of the substrate base. The volume of polycrystalline diamond material comprises a generally conical surface, an apex centered about a longitudinal axis extending through a center of the substrate base, a flat cutting surface extending from a first point at least substantially proximate the apex to a second point on the cutting element more proximate a lateral side surface of the substrate base. Another cutting element is disclosed, as are a method of manufacturing and a method of using such cutting elements.

It is an object of the invention to provide a technique that contributes to rationalization of dust collection, in a dust collecting attachment for use on a power tool. Dust collecting attachments 250, 350 are used on a power tool 201 having a tool body 203, a tool bit 209 which can be coupled to a front end region of the tool body 203, and an auxiliary handle 208 attached to the tool body 203. The dust collecting attachments 250, 350 include dust collecting members 251, 351, respectively, which can be attached to the auxiliary handle 208 in such a manner as to surround the front end region of the tool body 203 around a longitudinal axis of the front end region in order to collect dust generated during operation by the power tool 201, and a connecting hose 273 for connecting the dust collecting members 251, 351 to a dust collector.

Systems and methods for processing drilling data. One embodiment provides a method comprising building user-designed contexts (which can be designated as built-in contexts) for drilling structures. The method also comprises orchestrating module execution within the user-designed contexts. The method further comprises providing data from the user-designed contexts to such modules via an interface. Some methods include monitoring drilling data to detect events (for instance departure from a pseudolog) and orchestrating module execution responsive thereto. The method can include exposing the orchestration of the execution of the module instances as a service. Moreover, some embodiments provide extra-contextual application program interfaces. In addition, or in the alternative, some embodiments schedule the orchestration of the modules based on declarations related to the inputs and/or outputs of the modules.

This invention provides a structure for gunpowder charge for charging gunpowders of different rates in combined fracturing perforation devices. The structure for gunpowder charge is convenient to mount and transport. In one embodiment, said structure for gunpowder charge comprises an inner gunpowder box located between adjacent perforating charges in the charge frame of a perforation device, and an outer gunpowder box attached to the outer wall of the charge frame, wherein said outer gunpowder box comprises one or two box units (2 or 4) with at least one claw at the inner side of said box unit, said claw can be locked into a groove or installation hole of the charge frame, and wherein said inner gunpowder box and said outer gunpowder box are charged with gunpowders of different burning rates.

A control and monitoring system controls and monitors a high power laser system for performing high power laser operations. The control and monitoring system is configured to perform high power laser operation on, and in, remote and difficult to access locations.

In at least some embodiments, a pulsed-electric drilling system includes a bit that extends a borehole by detaching formation material with pulses of electric current, and a drillstring that defines at least one path for a fluid flow to the bit to flush detached formation material from the borehole. A feed pipe transports at least a part of said fluid flow to said path, and the feed pipe is equipped with a cooling mechanism to cool the fluid flow. The use of a cooled fluid flow may enhance the performance of the pulsed-electric drilling process.

A method for managing a drilling operation, including generating, by a first sensor and a second sensor of a bottom hole assembly (BHA), a first time based data log and a second time based data log, respectively, representing a borehole parameter along a drilling trajectory, determining, by a computer processor of the BHA and during the drilling operation, a time shift by comparing the first time based data log and the second time based data log, where offsetting the first and second time based data logs by the time shift maximizes a correlation factor of the first and second time based data logs, and determining, within a pre-determined time period from generating the first and second time based data logs, a drilling speed based on the time shift and a pre-determined distance between the first sensor and the second sensor.

Apparatus and method for automated drilling of a borehole in a subsurface formation. In one embodiment, a method includes selecting at least one control variable. A drilling performance objective having a value that is influenced by drilling of the borehole using the at least one control variable is defined. A first interval of the borehole is drilled maintaining the at least one control variable at a first value. A second interval of the borehole is drilled maintaining the at least one control variable at a second value. A third interval of the borehole is drilled maintaining the at least one control variable at a third value. The third value is selected based on a comparison of the values of the drilling performance objective while drilling the first interval and second interval to a predetermined optimal value of the drilling performance objective.

A method for reducing the friction forces between tubulars, for example coiled tubing in casing includes mixing a selected suspending agent and surfactant and polymer particles in oil, then adding the mixture to water and pumping the mixture down the tubing. The mixture is particularly useful in coiled tubular drilling inside casing of an oil or gas well. The formulation has also been found to reduce corrosion on metal surfaces.

Methods and apparatus are described to drill and complete wellbores. Such wellbores include extended reach horizontal wellbores, for example in shales, deep subsea extended reach wellbores, and multilateral wellbores. Specifically, the invention provides simple threaded subassemblies that are added to existing threaded tubular drilling and completion equipment which are used to dramatically increase the lateral reach using that existing on-site equipment. These subassemblies extract power from downward flowing clean mud, or other fluids, in an annulus to provide additional force or torque on tubular elements within the wellbore, while maintaining circulation, to extend the lateral reach of the drilling equipment and completion equipment. These added elements include combinations of The Leaky Seal™, a Cross-Over, The Force Sub™ and The Torque Sub™. The use of such additional simple elements allow lighter drilling equipment to be used to reach a given lateral distance, therefore reducing drilling costs.

Embodiments of the invention relate to polycrystalline diamond compacts (“PDCs”) comprising a polycrystalline diamond (“PCD”) table including at least a portion having aluminum carbide disposed interstitially between bonded-together diamond grains thereof, and methods of fabricating such PDCs. In an embodiment, a PDC includes a substrate, and a PCD table bonded to the substrate. The PCD table includes a plurality of bonded-together diamond grains defining a plurality of interstitial regions. The PCD table further includes aluminum carbide disposed in at least a portion of the plurality of interstitial regions.

Disclosed herein is a method of delineating a second wellbore from a first wellbore. The method includes, emitting acoustic waves from a tool in the first wellbore, receiving acoustic waves at the tool reflected from the second wellbore, and determining orientation and distance of at least a portion of the second wellbore relative to the tool.

A method of monitoring a well for unwanted formation fluid influx is disclosed. Measurements of well outflow are acquired during a period in which drilling operations are performed for the well. Occurrences of stagnant flow events during the period are determined. An outflow signature is generated from the well outflow measurements for each stagnant flow event. The outflow signatures are displayed sequentially in time of occurrence. Each outflow signature is analyzed for an anomaly.

Method and apparatus for controlling rock drilling with a percussion device belonging to a rock drill to deliver stress waves to rock through a tool by pushing the tool against the rock by means of a feed motor and rotating simultaneously the tool by means of a rotation motor, whereby the maximum feed force is determined, pressure medium is supplied to the feed motor and to the rotation motor and the feed force is controlled according to the drilling conditions. The feed force is controlled on the basis of the feed speed and the rotation torque. The apparatus has a load control valve which controls the feed.

Nozzles for drilling tools, such as rotary-type drag bits and roller cone bits, a drilling tool and drilling assembly comprising nozzles, and methods of conveying drilling fluid through a nozzle for use in drilling subterranean formations are provided. A nozzle may include a substantially cylindrical nozzle body having an axis and an inlet port with a primary passage extending therethrough, and at least one secondary passage that diverges from the primary passage at an exit port.

A vibrational tool and method is disclosed, which may be utilized to assist in lowering a drill string into a wellbore. In one embodiment, a reciprocating member and a symmetrical rotating member are mounted within a vibrational tool housing. The reciprocating member is urged in one embodiment by a spring assembly toward the rotating member whereby engagement surfaces on the reciprocating member and rotating member encounter each other. As the rotating member rotates, variable surfaces on the engagement surface cause the reciprocating member to reciprocate as the variable surfaces follow or cam with respect to each other during rotation. The resistance to rotation by engagement surfaces and spring assembly, and mass of the rotating member, result in vibrational forces, when drilling fluid flows through the vibration tool housing.

A cutting element for a drill bit includes an outer support element and an inner rotatable cutting element, a portion of which is disposed in the outer support element, where the inner rotatable cutting element has a body with a non-planar cutting face.

An adjustable bent drilling tool capable of changing in situ drilling direction to facilitate horizontal drilling. The drilling tool may be controlled from the surface and eliminates the need to bring the tool to the surface for reconfiguration. In one embodiment, the drilling tool utilizes a communications module to communicate with upstream sections of the tool. The communications module is connected to a programmable electronic control module which controls an electric motor. A hydraulic valve assembly follows the control module, which receives input signals and controls a pilot piston between two fixed points of a mid-assembly typically located adjacent to and downstream of the hydraulic valve assembly on the drill tool. A lower assembly is attached to the drill tool immediately following the mid-assembly, and provides both a safety release sub-assembly as well as a bendable sub-assembly which directs the adjustable drill tool to change drilling angle and direction.

Expandable apparatus for use in subterranean boreholes include at least one member configured to move between a retracted position and an extended position. A latching member disposed in the tubular body may selectively retain the at least one member in the retracted position. Methods of operating an expandable apparatus include securing at least one member of the expandable apparatus in a retracted position by engaging an inner wall of a tubular body with at least one latch member disposed in at least one aperture formed in a latch sleeve.

Expandable apparatus for use in subterranean boreholes include at least one member configured to move between a retracted position and an extended position. Components of the expandable apparatus may include at least one surface for removing debris proximate to the tubular body. Components of the expandable apparatus may be configured to enable the expandable apparatus to increase a diameter of a subterranean borehole by greater than twenty percent. Components of the expandable apparatus may be configured to restrict fluid flow to nozzle assemblies. The expandable apparatus may include a protect sleeve having a push sleeve disposed therein. Methods of operating an expandable apparatus may include removing debris with a surface of the expandable apparatus. Methods of operating an expandable apparatus may also include selectively flowing fluid to nozzle assemblies.

A rotary joint for use in directional control of a subterranean rotary steerable drilling apparatus. The rotary joint is formed by mated spherical-shaped sockets, each of which is connected with a hollow rod. By virtue of this arrangement, a continuous passageway is provided for fluid to flow through the rotary joint, which fluid may be used for cooling the rotary joint during operation of the rotary steerable drilling system.

A THz frequency range antenna is provided which comprises: a semiconductor film (3) having a surface adapted to exhibit surface plasmons in the THz frequency range. The surface of the semiconductor film (3) is structured with an antenna structure (4) arranged to support localized surface plasmon resonances in the THz frequency range.

A tracking system for tracking an eye including a light source projecting light toward a display surface in a sequential pattern, one or more reflectors associated with an optical device, where the one or more reflectors reflect the pulses of light from the display source, one or more photo detectors, where the photo detectors detect reflected pulses of light from the light source, and a system that measures pulse timing relative to horizontal and vertical pattern to compute a gaze angle of the eye.

A radiation detector is disclosed that includes a scintillation crystal and a plurality of photodetectors positioned to detect low-energy scintillation photons generated within the scintillation crystal. The scintillation crystals are processed using subsurface laser engraving to generate point-like defects within the crystal to alter the path of the scintillation photons. In one embodiment, the defects define a plurality of boundaries within a monolithic crystal to delineate individual detector elements. In another embodiment, the defects define a depth-of-interaction boundary that varies longitudinally to vary the amount of light shared by neighboring portions of the crystal. In another embodiment the defects are evenly distributed to reduce the lateral spread of light from a scintillation event. Two or more of these different aspects may be combined in a single scintillation crystal. Additionally, or alternatively, similar SSLE defects may be produced in other light-guiding elements of the radiation detector.

A detector for detecting ionizing radiation comprises a scintillator 10 selected to emit light in response to incidence thereon of radiation to be detected, at least one detector 16 for detecting said emitted light, and at least one optical waveguide 12 for transmitting said emitted light to said detector 16. The optical waveguide typically comprises a flexible solid or hollow fiber that can be incorporated into a flexible mat or into a fiber-reinforced structure, so that the detector is integrated therewith.

A sensor includes a collector, an emitter and a base-region barrier formed as an inverted bipolar junction transistor having a base substrate forming a base electrode to activate the inverted bipolar junction transistor. A level surface is formed by the collector, the emitter and the base-region barrier opposite the base substrate such that when the level surface is exposed to charge, the charge is measured during operation of the bipolar junction transistor.

A particle beam sensor comprising: scattering means providing a surface for intercepting obliquely a path of a particle beam thereby to permit a scattering of particles from the particle beam by the scattering means; sensor means responsive to receipt of one or more said scattered particles to generate a sensor signal; aperture mask means arranged between the scattering means and the sensor means to present to the scattering means a screen opaque to said scattered particles and having at least one aperture through which an unobstructed view of the scattering means is provided to the sensor means, the aperture (s) thereby permitting selection of all of those particles scattered by the scattering means which may be used to form at the sensor means an image representative of at least a part of a foot print cast by the particle beam upon the scattering means. By scattering particles from a sectional area of a particle beam, scattered beam particles can be used more efficiently compared to existing techniques.