Abstract: A method for selecting a grasp posture of a dual-arm robot includes: setting a fitness value range, an iteration quantity threshold, and a fitness function; calculating the fitness value of the population, determining whether the population is within the value range, ending an iteration if the population is within the value range or continuing to determine whether a quantity of iterations reaches the iteration quantity threshold if the population is not within the value range, ending the iteration if the quantity of iterations reaches the iteration quantity threshold or performing crossover and mutation operations if the quantity of iterations does not reach the iteration quantity threshold, and dynamically selecting a gene retention strategy based on an iteration depth and a fitness value to retain a gene; updating a gene population representing a grasping position and performing determining cyclically; and obtaining an optimal target corresponding to dual arms after the iteration.

Abstract: A method for controlling the movement of an X-ray source via a suspension device includes obtaining, during a movement of the suspension device along the rail, a first speed of the suspension device at the first reference point. The first reference point may correspond to a first target position. The method may also include determining whether the first speed of the suspension device at the first reference point is less than a threshold speed. In response to a result of the determination that the first speed of the suspension device at the first reference point is less than the threshold speed, the method may further include actuating a control device to move the suspension device to the first target position.

Abstract: Various methods and systems are provided for a medical imaging system C-arm. In one embodiment, an imaging system comprises a C-arm including an inner circumferential wall forming a first pair of grooved flanges and the outer circumferential wall forming a second pair of grooved flanges, where each of the first pair of grooved flanges and second pair of grooved flanges comprises a composite material. A C-shaped portion of the C-arm may be configured to rotate isocentrically around a rotational axis.

Abstract: Methods and system are provided for an imaging system. In one example, the imaging device, comprises a curved arm and a carrier that engages and supports the curved arm, wherein the curved arm is configured to move relative to the carrier. The imaging system further comprises a belt extending through the carrier and traversing around a periphery of the curved arm.

Abstract: A radiation imaging system includes a plurality of radiation imaging apparatuses each of which includes a radiation detecting unit that performs an imaging operation for capturing a radiation image based on radiation radiated from a radiation generating apparatus, a control apparatus that communicates with the plurality of radiation imaging apparatuses, a calculation unit that calculates information indicating whether a part or all of pixels of the radiation image are saturated, and an image acquiring unit that acquires a radiation image from a radiation imaging apparatus selected from among the plurality of radiation imaging apparatuses based on the information.

Abstract: An X-ray imaging system is provided. The X-ray imaging system includes an X-ray radiation source, an X-ray detector, and a C-arm. The C-arm has the X-ray radiation source disposed on a first end and the X-ray detector disposed on a second end opposite the first end. The X-ray imaging system also includes a motorized system configured to rotate the C-arm about three different rotational axes.

Abstract: A radiographic imaging apparatus in which a radiation source support unit supports a radiation source is adapted to be capable of being quickly carried to a use position in a small radius. A radiographic imaging apparatus includes a leg unit that includes three or more wheel units and is capable of traveling on an apparatus-placement surface by using wheels, a body unit that is held on the leg unit, an arm unit as a radiation source support unit that is connected to the body unit, a radiation source that is mounted on the arm unit, a battery that is received in the body unit and drives the radiation source, and a circuit that is received in the body unit and relates to the drive of the radiation source. The wheel unit is formed of a revolving caster.

Abstract: This X-ray apparatus for rounds includes an X-ray generator capable of moving up and down in a vertical direction, a holding frame that holds a compression spring or a tension spring that expands and contracts as the X-ray generator moves up and down such that the compression spring or the tension spring is expandable and contractable, that holds a wire rope that transmits an elastic force of the compression spring or the tension spring to the X-ray generator and a pulley around which the wire rope is wound and which rotates, and that supports the X-ray generator such that the X-ray generator is movable up and down, and a support column that extends in the vertical direction and houses the holding frame such that the holding frame is detachable and upwardly exposable.

Abstract: A system is provided. The system includes a C-arm with an X-ray source and an X-ray detector mounted thereon opposite each other. The system also includes a carrier coupled to the C-arm and configured to rotate the C-arm relative to the carrier. The system further includes a base and a multiple robotic arms coupling the carrier to the base. Each robotic arm of the multiple robotic arms includes two articulated segments and at least two rotary joints.

Abstract: A contactless and/or non-invasive system and method of determining the rotational state and/or speed of a rotor for an X-ray tube including a liquid metal bearing includes a vibration sensor that is affixed to the exterior of the x-ray tube and is utilized to detect the vibrations generated by the spinning of the rotor and liquid metal bearing assembly within the x-ray tube. The x-ray tube has signature vibration signal based on the construction and rotor speed of the x-ray tube. The system and method of the invention used to detect the rotor state/speed includes a sensor to pick up the vibration from the x-ray tube and perform signal processing, and a software algorithm stored within the device or on an operably connected device or system that can analyze the vibration data from the sensor to indicate whether the anode in the x-ray tube is spinning.

Abstract: A medical examination or treatment facility includes a C-arm, arranged on a support bracket of a robot configured to move the C-arm in space. In an embodiment, the C-arm is made up of a plurality of arm elements in the form of sheet metal parts and at least one coupling unit including at least one cast metal part for coupling the C-arm to the support bracket.

Abstract: A radiological imaging device having a longitudinal axis includes a gantry suitable to perform radiological imaging and defining an area of analysis, a bearing structure supporting the gantry; and a robotic arm suitable to move a medical instrument with respect to the area of analysis. The bearing structure includes a guide defining a translation axis parallel to the longitudinal axis and a carriage suitable to move the gantry and robotic arm along the translation axis.

Abstract: The disclosure relates to a mobile X-ray device having an equipment cart that is movable on wheels and has a lifting device on which a support assembly is arranged. A C-arm is mounted to the support assembly so as to be displaceable along the circumference of the support assembly, wherein the C-arm has an X-ray source and an X-ray receiver arranged opposite the X-ray source. In order to simplify the handling of a mechanical zoom on mobile X-ray devices, a motion controller is provided by which, in any given pose of the C-arm, a movement of the C-arm is controlled in such a way that the central axis extending between X-ray source and X-ray receiver is fixed in space.

Abstract: An x-ray positioning stand, for holding an x-ray generator, includes a base having a primary base member, a first extension arm, and a second extension arm. The primary base member extends in a longitudinal direction along the length from a first end to a second end, and extends in a transverse direction along the width from a front side to a rear side. The first extension arm is pivotably connected to the primary base member proximate the first end and the second extension arm is pivotably connected to the primary base member proximate the second end. The stand also includes a support rod having a lower end connected to a central portion of the primary base member and an upper end having an attachment head connectable to the x-ray generator, and configured for supporting the x-ray generator over a subject to be imaged. Each of the first extension arm and the second extension arm are pivotable from a stored position to a deployed position.

Abstract: According to the present invention, a highly safe moving-type radiation device can be provided. In the case of a conventional configuration using tension springs, if a spring is severed, the fragments will separate from each other permanently. Therefore, the present invention uses compression spring 8a and 8b instead. According to the spring mechanism of the present invention, even if a shaft is about to move largely in accordance with the severing of a spring, fragments of the spring, which has become stuck each other and immovable, interfere and prevent the movement of the shaft. What has been devised in the present invention is a junction spring seat that links a plurality of compression springs 8a and 8b. With this, even in cases where the compression springs 8a and 8b are linked in series, the compression springs 8a and 8b will not be buckled.

Abstract: The present invention provides a moving type radiation device improved in usability. The stroke of an intermediate member in a conventional configuration can be increased when an effective diameter of a pinion with respect to an effective diameter of a lower sprocket is determined so that a magnitude of a relative movement that occurs when a lower sprocket and the pinion between an X-ray tube and the intermediate member becomes larger than the magnitude of the relative movement between the X-ray tube and the intermediate member. In the device according to the present invention, the intermediate member moves further toward the floor side than in a conventional device. The operator can move the device while feeling high operability in a state in which the visibility is not interrupted by the intermediate member.

Abstract: Provided is a mobile X-ray imaging device having a foldable arm unit equipped with an X-ray tube unit, and a storage concave for storing the folded arm unit on the front side of a main body. An end of the arm unit fixed to the main body side is made slidable with respect to the main body. With this configuration, it is possible to provide the mobile X-ray imaging device having a high degree of flexibility in arranging the X-ray tube when imaging is performed, and also the forward view is never be obstructed by the device in transit.

Abstract: A device is provided. The device includes an orbital clutch and brake assembly configured to couple to a C-arm rotation device that enables the C-arm to rotate in an orbital direction relative to the C-arm rotation device. The orbital clutch and brake assembly includes a housing, a roller, and a brake pad. The roller and brake pad are disposed within the housing. The brake pad is configured to directly contact the roller and to not contact the C-arm when the orbital clutch and brake assembly applies a braking force to the C-arm.

Abstract: An X-ray emitter includes an emitter housing in which an X-ray tube is disposed and held in the emitter housing by a fixing facility. The fixing facility includes a fixed bearing disposed on the cathode side and a floating bearing disposed on the anode side. At least the floating bearing has at least one damping element. In the X-ray emitter, the X-ray tube is aligned inside the emitter housing and fixed in a respectively low-vibration or vibration-damped manner, resulting in a more stable focus position relative to a beam exit and also a correspondingly improved image quality.

Abstract: A radiation image capturing system including: a radiation image capturing apparatus which is portable and reads emitted radiation as image data; and a plurality of consoles, wherein when the radiation image capturing apparatus is attached to an attachment section which is associated with one console among the plurality of consoles, the one console determines whether the radiation image capturing apparatus is registrable, and when the one console determines that the radiation image capturing apparatus is registrable, the one console registers the radiation image capturing apparatus, and in a case where the radiation image capturing apparatus is already registered in another console among the plurality of consoles, the another console cancels registration of the radiation image capturing apparatus only when the one console registers the radiation image capturing apparatus.

Abstract: A mobile x-ray apparatus having wheels for manual transport and an x-ray tube support attached to a base. The apparatus may be rolled by pushing and/or pulling the base, the support, or the x-ray tube. A brake is associated with at least one of the wheels to prevent rolling the apparatus when manually positioning the x-ray tube. The brake may be engaged from an actuator on the tube head, on the support, or on the base.

Abstract: A mobile X-ray imaging apparatus has an angle sensor and a movement calculation circuit that controls the driving of drive wheels based on the turning angle of auxiliary wheels relative to a straight moving direction of the base unit when a fine movement switch instructs movement of the base unit in the fine movement mode. The turning angle of auxiliary wheels is detected by a turning angle sensor and the rotation of the pair of drive wheels is controlled by the movement calculation circuit as the auxiliary wheels turns to the straight moving direction.

Abstract: An X-ray CT apparatus including an X-ray generator, an X-ray detector, a support part, and a base that rotatably supports the support part. The support part includes an exterior part made of carbon fiber reinforced plastic, and the X-ray generator and the X-ray detector are supported by the exterior part while being opposed to each other. The base rotatably supports the support part such that the X-ray generator and the X-ray detector turn about a turning axis.

Abstract: A method for recording a scan from a series of 2D X-ray projections using a C-arm X-ray apparatus allows an analytical volume reconstruction of a disk-shaped region of interest. The C-arm X-ray apparatus has a coherent, flat focus trajectory comprising three sections on which the focus of the X-ray source is moved with recording of X-ray projection views. The X-ray source emits a cone beam in the direction of an imaging X-ray detector, such as in particular a flat panel detector FPD. In some implementations, the cone beam is configured as a fan beam with a fan angle in the plane of the focus trajectory, which contains the ROI with the virtual scan center in its center, wherein the central ray of the fan beam is located on the bisector of the fan angle, and stands vertically on the ray inlet window.

Abstract: An X-ray fluorescence spectrometer includes: a sample stage configured to place a sample thereon; an X-ray source configured to irradiate the sample with primary X-rays; a detector, which is configured to detect fluorescent X-rays produced from the sample irradiated with the primary X-rays, and which includes an X-ray incident window formed by a window material through which fluorescent X-rays is transmittable; and a gas blowing mechanism configured to blow a gas to at least one of an outer surface of the X-ray incident window and the sample stage.

Abstract: In an exemplary embodiment, an imaging apparatus comprises an arm assembly coupled to an imaging arm. The arm assembly includes a shoulder joint, an elbow joint, and an articulation assembly. The shoulder joint is configured to travel a vertical distance in a substantially linear fashion and provide rotational movement. The imaging arm comprises a first end and a second end. As such, the imaging apparatus is configured to provide radial motion along a path equal to the length of the arm assembly and the imaging arm along the vertical distance and the horizontal distance of the shoulder joint. The imaging apparatus may also comprise a movable cabinet, a monitor, and a control, with the arm assembly coupled to the movable cabinet. Furthermore, the imaging arm may comprise an x-ray source and a sensor, with the monitor displaying data detected by the sensor.

Abstract: A mobile radiation imaging apparatus includes a radiation generation unit configured to generate radiation, a cart, a supporting member formed on the cart and configured to hold the radiation generation unit in a movable manner with respect to the cart, a detection unit configured to detect arrangement of the radiation generation unit in a particular non-imaging position, and a control unit configured to limit a motion of the supporting member according to a detection result by the detection unit.

Abstract: A C-arm sleeve for preserving the sterility of a C-arm. The C-arm sleeve includes a C-frame drape configured to cover the C-frame of the C-arm. The C-arm sleeve also includes an image intensifier drape configured to be placed over an image intensifier of the C-arm. The C-arm sleeve further includes a tube-head drape configured to be placed over a tube-head of the C-arm.

Abstract: An X-ray imaging apparatus comprises an X-ray generation unit; a plurality of supporting members configured to support the X-ray generation unit; and an accommodation unit configured to accommodate the X-ray generation unit and the plurality of supporting members, wherein the accommodation unit is formed by bringing a first member and a second member into contact with each other, each of the plurality of supporting members is connected to the first member by a first connecting portion that is rotatable and to the X-ray generation unit by a second connecting portion that is rotatable, and a support height of the X-ray generation unit supported by the supporting members can be adjusted in accordance with a distance between the first member and the second member.

Abstract: An X-ray imaging apparatus comprises an X-ray source; a housing configured to accommodate the X-ray source; and a plurality of supporting legs each connected to the housing via a movable connecting portion and configured to support the housing, wherein each of the supporting legs can change, by the movable connecting portion, a support angle made by a ground plane and the supporting leg.

Abstract: An X-ray stand includes a device that compensates for distortions caused by weight. The stand includes a horizontal bracket. The device for distortion compensation includes an inclination-angle transmitter that generates an inclination signal as a function of an inclination angle of the bracket. The device also includes a control device that receives the inclination signal from the inclination-angle transmitter, a motor drive that is activated by the control device, and an adjustment device that is driven by the motor drive and is configured to adjust the inclination angle of the bracket. The control device activates the motor drive such that any deviation of the inclination angle of the bracket from a predefined inclination angle is reduced.

Abstract: Embodiments of backscatter inspection systems include features to enable inspection of irregular surfaces, tight spacer, and other hard-to-reach places. Some embodiments include arms that maneuver a scan head with at least three degrees of freedom, and some embodiments include arms that maneuver a scan head with at least seven degrees of freedom. Some embodiments include proximity detectors on a scan head or base, detect contact with an object being inspected, and to slow or stop the motion of the system accordingly. Some compact embodiments scan the interior of an object from within, and include a rotating, low-energy source of penetrating radiation, and at least one backscatter detector, which may be stationary, or may rotate with the source.

Abstract: With an X-ray apparatus for round visit of this invention, when a brake operation is carried out, a CPU performs deceleration control (braking current control at c and short brake control at e) of a movable carriage instead of immediately driving electromagnetic brakes, and drives the electromagnetic brakes at time f. Therefore, a great shock does not occur to the apparatus, and there is no possibility of the operator colliding with the apparatus. Since the deceleration control of the movable carriage is carried out in advance, the apparatus does not stop suddenly and does not impair the floor. As a result, the X-ray apparatus for round visit is realized, in which no great shock occurs to the apparatus at times of deceleration, and which is also safe for the operator.

Abstract: Systems and methods for braking and releasing one or more pivot joints used in an X-ray positioning device are described. The systems and methods use a support arm that extends between a main assembly of the x-ray positioning device and an X-ray imaging assembly with an X-ray source and an X-ray detector that are disposed nearly opposite to each other. The support arm includes one or more pivot joints (such as horizontal, lateral, and/or orbital pivot joints) that allow the imaging assembly to move with respect to the main assembly. The pivot joints can each be connected to an automated braking system that is capable of selectively locking and unlocking a corresponding pivot joint, as indicated by a user-controlled switching mechanism. The braking systems containing multiple pivot joints can be individually controlled by separate switching mechanisms or simultaneously controlled by a single switching mechanism. Other embodiments are described.

Abstract: A mobile radiography apparatus has a portable transport frame and a sectioned vertical column mounted on the frame and defining a vertical axis and having a base section having a fixed vertical position relative to the vertical axis and at least one movable section that is translatable to a variable vertical position along the vertical axis. A counterbalance apparatus is coupled to the at least one movable section of the vertical column with an actuator that is energizable to translate the at least one movable section along the vertical axis. A boom apparatus supports an x-ray source and is coupled to the at least one movable section for vertical displacement of the boom apparatus to a height position. A height sensing element provides a signal that is indicative of the height position of the boom apparatus.

Abstract: An imaging apparatus includes: a rotator having a shape of a perforated circular plate and rotating around a rotating axis of a center of the perforated circular plate; and a supporter having a perforated circular plate and one side of which is connected to one side of the rotator such that the rotator is restricted only to rotation movement. The supporter includes a supporter opening/closing part a part of which is separated along the rotating axis and then rotates by a predetermined angle around the rotating axis, and the rotator includes a rotator opening/closing part a part of which integrally moves with the supporter opening/closing part.

Abstract: An X-ray tube mount for mounting an X-ray tube assembly to the rotating disk assembly of a CT imaging system, said X-ray tube mount comprising: a housing having an inner end and an outer end, wherein said inner end of said housing is located closer to the center of rotation of the rotating disk assembly than said outer end of said housing; and at least one mounting construct for mounting said housing to the rotating disk assembly, wherein said at least one mounting construct is disposed intermediate said inner end of said housing and said outer end of said housing.

Abstract: An X-ray generation unit and an X-ray detection unit are held by an arm. Image data is generated based on X-ray projection data which is generated by the X-ray detection unit. A first support member supports the arm and rotates the arm in a first rotation direction. A second support member supports the first support member. The second support member rotates the first support member around a rotation center in a second rotation direction perpendicular to the first rotation direction. A movement unit can move the second support member in an up and down direction.

Abstract: In order to provide an X-ray CT apparatus including a rotating portion capable of enduring a high speed rotation and tilting, the rotating portion includes a cylinder portion 42, a ring portion 41 that is disposed at a position which is offset from the center in the direction of a rotation axis 32 of the cylinder portion 42, and the cylinder portion 42 and the ring portion 41 are supported by spoke portions 43 to 46. An X-ray tube and one or more circuit units are fixed on the inner wall of the cylinder portion 42. Thereby, the centers of gravity of an X-ray detection unit and the circuit units can be positioned at the center position in the direction of the rotation axis 32 of the cylinder portion 42.

Abstract: A diagnostic imaging system, which can be a mobile or stationary surgical CT imaging system or an MRI system, comprises an internal airflow cooling system that includes an air intake opening and an air outtake opening that are positioned near the ground and direct air flow away from the sterile surgical field.

Abstract: The system for the inspection and imaging of insulated pipes and vessels using backscattered gamma radiation and X-ray fluorescence includes a frame having a pair of coaxial rings adapted for coaxial mounting about the insulated pipe, vessel or the like. A pair of rotating supports are rotatably mounted within the pair rings for driven rotation thereof. A plurality of horizontal supports are secured to, and extend between, the pair of rotating supports such that each of the horizontal supports extends along a direction parallel to an axis of the insulated pipe. A plurality of inspection modules are slidably mounted to the horizontal supports. Each inspection module includes at least one radiation source, an X-ray fluorescence detector and a backscattered gamma radiation detector. The plurality of inspection modules are linearly translated along the axial direction of the pipe, and also circumferentially rotated therearound for simultaneous, three-dimensional inspection of the pipe body.

Abstract: The c-arm x-ray system according to the present invention presents a system that provides at least one x-ray beam projection and an auxiliary projection without the need to rearranging or move elements of the c-arm to avoid inaccuracies through mechanical deflection of the supporting c-arm. This is achieved by comprising a main x-ray source, and at least one auxiliary x-ray source with a lower continuously radiated power than the main x-ray source and mechanically coupled to the main x-ray source, which is formed as a cold carbon nanotube based field emitter.

Abstract: Systems and methods for obtaining two-dimensional images of an object, such as a patient, in multiple projection planes. In one aspect, the invention advantageously permits quasi-simultaneous image acquisition from multiple projection planes using a single radiation source. An imaging apparatus comprises a gantry having a central opening for positioning an object to be imaged, a source of radiation that is rotatable around the interior of the gantry ring and which is adapted to project radiation onto said object from a plurality of different projection angles; and a detector system adapted to detect the radiation at each projection angle to acquire object images from multiple projection planes in a quasi-simultaneous manner. The gantry can be a substantially “O-shaped” ring, with the source rotatable 360 degrees around the interior of the ring. The source can be an x-ray source, and the imaging apparatus can be used for medical x-ray imaging.

Abstract: The invention relates to a medical x-ray imaging apparatus which includes a support construction (1) supporting a substantially ring-shaped structure (2), an O-arm (2), which in turn supports imaging means (21, 22) and which O-arm (2) is arranged with an examination opening (4). The imaging means (21, 22) are arranged movable within the O-arm (2). The examination opening (4) is arranged for its predominant portion substantially of the shape of an arch of a circle but to comprise an extension, within the sector covered by which extension the distance from the centre of said arch of the circle to the edge of the examination opening (4) is longer than within the prevailing portion of the examination opening (4) being substantially of the shape of an arch of a circle.

Abstract: An imaging system and methods including a gantry defining a bore and an imaging axis extending through the bore, and at least one support member that supports the gantry such that the imaging axis has a generally vertical orientation, where the gantry is displaceable with respect to the at least one support member in a generally vertical direction. The imaging system may be configured to obtain a vertical imaging scan (e.g., a helical x-ray CT scan), of a patient in a weight-bearing position. The gantry may be rotatable between a first position, in which the gantry is supported such that the imaging axis has a generally vertical orientation, and a second position, such that the imaging axis has a generally horizontal orientation. The gantry may be displaceable in a horizontal direction and the system may perform a horizontal scan of a patient or object positioned within the bore.

Abstract: An x-ray emitter housing includes a first housing part and a second housing part that are connected to one another in a form-fit manner using an axially acting threaded ring.

Abstract: The invention relates to a medical computed tomography imaging apparatus which includes a support construction (1) which is arranged to support a substantially ring-shaped structure (2) supporting x-ray imaging means (21, 22), which x-ray imaging means (21, 22) are arranged within said substantially ring-shaped structure supporting the imaging means (2) and movable within said substantially ring-shaped structure supporting the imaging means (2), which ring-shaped structure (2) supporting the imaging means (21, 22) includes an examination opening (4), whereto the object to be imaged can be positioned for imaging. According to the invention, at least one display (11) is arranged to the apparatus. The display is arranged in functional connection with at least one video camera (12), which at least one video camera (12) is arranged in connection with said ring-shaped structure (2) and as aimed, or so that it can be aimed inside said examination opening (4).

Abstract: The invention relates to a medical computed tomography apparatus which includes a support construction (1) supporting a substantially ring-shaped O-arm (2), which in turn supports imaging means (21, 22). The cross-section of the outer cover (3) of the O-arm in a direction perpendicular with respect to the central axis of said ring-shaped structure (2) is for its prevailing portion arranged substantially of the shape of an arch of a circle but to comprise a cut, and within the sector covered by the cut the distance from the center of said arch of a circle to the edge of the outer cover (3) is shorter than within said portion of the outer cover (3) substantially of the shape of an arch of a circle.

Abstract: An X-ray device including a C-arm movably guided on a mount is provided. A radiation source and a radiation detector are arranged on the C-arm. The radiation source and the radiation detector are connected to the C-arm by cables fed in from outside, the cables being arranged on a cable clamp that may be moved at least in segments along the C-arm.

Abstract: Device comprising: a chassis (1) which supports the entire assembly, a telescopic column (2) which comprises a lower fixed portion (5) rotating with respect to a vertical axis, and at least one upper mobile portion (6), a telescopic arm (3) that moves along the vertical column and that supports an x-ray emitter (4) at its end, wherein the telescopic arm-head assembly can be moved from the lower position of the mobile column in its retracted position to the upper position of the mobile column in its extended position, and also in that all the movements of the column are manual and have a mechanical balancing mechanism which comprises a first mechanism consisting of a spring, a block and tackle, and a variable radius pulley all housed in the fixed portion of the column, and a second balancing mechanism consisting of a recovery pulley and a two-radii pulley which balances the weight between the input of the cable and that of the telescopic arm and head assembly.