Abstract: An automated product dispenser for dispensing a product from a supply of product is provided. The automated product dispenser includes a chassis assembly, a drive assembly, and an isolation member. The chassis assembly includes a chassis frame, and the drive assembly includes a motor, a drivetrain, and a drivetrain housing. The isolation member mounts the drive assembly to the chassis assembly such that the drive assembly is substantially spaced apart from the chassis frame. A related method of inhibiting vibration transmission in an automated product dispenser also is provided.

Abstract: It is provided a cooling fan module having: a fan shroud; a fan propeller cutout, which is formed in the fan shroud; a motor mount which is mechanically connected to the fan shroud by means of struts which are located at the rear viewed in the flow direction; a motor, which is mounted at least partially in the motor mount; a fan propeller which is arranged in the fan propeller cutout and which is driven rotationally about a rotational axis R by the motor. The fan propeller has a plurality of blade elements. All the elements of a group which has at least one of the struts and at least one of the blade elements are forward-sickled or rearward-sickled.

Abstract: An automated product dispenser for dispensing a product from a supply of product is provided. The automated product dispenser includes a chassis assembly, a drive assembly, and an isolation member. The chassis assembly includes a chassis frame, and the drive assembly includes a motor, a drivetrain, and a drivetrain housing. The isolation member mounts the drive assembly to the chassis assembly such that the drive assembly is substantially spaced apart from the chassis frame. A related method of inhibiting vibration transmission in an automated product dispenser also is provided.

Abstract: A linear compressor and a refrigerator including a linear compressor are provided. The linear compressor may include a compressor casing connected to each of a suction inlet, through which a refrigerant may be introduced, and a discharge outlet, through which the refrigerant may be discharged, a compressor body mounted within the compressor casing, within which the refrigerant suctioned in through the suction inlet may be compressed due to a linear reciprocating motion of a piston in an axial direction of the compressor casing and discharged into the discharge outlet, and at least one plate spring disposed on each end of the compressor body in the axial direction.

Abstract: An air mover comprising a housing with a top portion is disclosed. A mounting bracket is recessed into the housing through the top portion of the housing. The mounting bracket comprises a plurality of top chords intersecting at a first portion of an inner web and a plurality of bottom chords intersecting at a second portion of the inner web. The mounting bracket also has a base plate coupled to the plurality of bottom chords. A motor is coupled to the base plate of the mounting bracket. An impeller is coupled to the motor. The air mover further comprises a housing cover that has an inlet ring positioned on the top portion of the housing. The housing cover is coupled to the mounting bracket via the mounting flanges and a portion of the inlet ring protrudes into the impeller inlet inside the housing.

Abstract: The invention relates to an air supply device (7), comprising a blade wheel (9) and a housing (13) which delimits the blade wheel relative to the surroundings at least to some extent.

Abstract: An engine assembly having an improved mounting system or assembly is disclosed. Features of this mounting system include having crankcase arms that are integrally formed with a crankcase of the engine assembly, having multiple mounting legs that each have a dedicated vibration damping subassembly and where the stiffness of at least two of the mounting legs is different (by varying the configurations of the corresponding vibration damping subassemblies), and using a mounting ring or base with having differently oriented mounting pads for securement of the corresponding mounting leg relative thereto.

Abstract: A clip device that can be fixed to and detached from a pipe as desired. A clip main body is provided with insertion holes into which pipes can be inserted, and elastic holding pieces that face the insertion holes. A bracket is separate from the clip main body and can be attached to and detached from the clip main body. The bracket is provided with an attachment portion that can be attached to a body (vehicle), and pressing portions that press the elastic holding pieces against the outer circumferences of the pipes in the state where the bracket has been assembled together with the clip main body.

Abstract: A rebound training device includes a frame, a footboard, and a plurality of resilient elements extending between and attached to the frame and the footboard to support the footboard above a supporting surface. A user standing on the footboard manually effects repeated vertical bouncing movement between upper and lower positions. The distance traveled by the footboard, the effort required to effect movement, and the stability thereof may be modified by selectively modifying the number, the length, the position, or the elasticity of the resilient members.

Abstract: A blower device may include a housing and a motor mounted in the housing via a motor holder. The motor holder may be held on the housing via a plurality of arms such that a movement of the motor relative to the housing is permitted and a transmission of vibrations of the motor to the housing is dampened. The motor holder, at least one arm of the plurality of arms and the housing may be configured as a unipartite plastics injection-moulded part. Each arm of the plurality of arms may have a plurality of sections. The plurality of sections may include a first section connected to the motor holder, a second section angled relative to the first section, and a third section angled relative to the second section and connected to the housing.

Abstract: An air mover comprising a housing with a top portion is disclosed. A mounting bracket is recessed into the housing through the top portion of the housing. The mounting bracket comprises a plurality of top chords intersecting at a first portion of an inner web and a plurality of bottom chords intersecting at a second portion of the inner web. The mounting bracket also has a base plate coupled to the plurality of bottom chords. A motor is coupled to the base plate of the mounting bracket. An impeller is coupled to the motor. The air mover further comprises a housing cover that has an inlet ring positioned on the top portion of the housing. The housing cover is coupled to the mounting bracket via the mounting flanges and a portion of the inlet ring protrudes into the impeller inlet inside the housing.

Abstract: A fan system, including at least: an axial flow blade, a support including a clamping element and multiple installation pins, and an external rotor motor including an external rotor. The installation pins are extended from the outside of the clamping element. The axial flow blade is disposed on the installation pins. The clamping element is fit on the external rotor of the external rotor motor. The fan system features simple and convenient assembling, reliable connection, high production efficiency, low requirement for workers, and low production cost.

Abstract: In one aspect, a centrifugal blower assembly is provided. The centrifugal blower assembly includes a housing defining an interior space and an impeller configured to channel an airflow within the interior space. A motor is coupled to the impeller and configured to rotate the impeller about an axis. The centrifugal blower also includes a plurality of mounting arms. Each mounting arm of the plurality of mounting arms includes a first end coupled to the housing and a second end coupled to the motor. Each mounting arm of the plurality of mounting arms has a cross-sectional profile that comprises a portion of an airfoil shape.

Abstract: A platform stabilization system comprises a support frame, a platform and a plurality of isolators each extending directly between the support frame and the platform. Each isolator permits linear movement of the platform relative to the support frame with three degrees of freedom and permits rotational movement of the platform relative to the support frame with three degrees of freedom. The isolators cooperate to form an isolation array supporting the platform directly within, and spacing the platform from, the support frame. The isolation array permits limited linear movement of the platform within the support frame with three degrees of freedom and permits limited rotational movement of the platform relative to the support frame with three degrees of freedom. The isolation array is substantially more resistant to linear movement of the platform than to rotational movement of the platform and does not rotationally constrain the platform.

Abstract: The invention relates to an arrangement for mounting an optical element, in particular in an EUV projection exposure apparatus, comprising at least one actuator which exerts a controllable force on the optical element; wherein between the actuator and the optical element a mechanical coupling in the form of a pin is embodied in such a way that, relative to the drive axis of the actuator, the ratio of the stiffness of the mechanical coupling in an axial direction to the stiffness in a lateral direction is at least 100; and at least one damping element which brings about a damping of a natural vibration form of the pin in a lateral direction.

Abstract: The invention concerns a raising apparatus for lifting sheets of material in tools, in particular punching and stripping tools, with a first spring element which possesses a first spring rate, and a second spring element which possesses a second spring rate.

Abstract: A platform stabilization system comprises a support frame, a platform and a plurality of isolators each extending directly between the support frame and the platform. Each isolator permits linear movement of the platform relative to the support frame with three degrees of freedom and permits rotational movement of the platform relative to the support frame with three degrees of freedom. The isolators cooperate to form an isolation array supporting the platform directly within, and spacing the platform from, the support frame. The isolation array permits limited linear movement of the platform within the support frame with three degrees of freedom and permits limited rotational movement of the platform relative to the support frame with three degrees of freedom. The isolation array is substantially more resistant to linear movement of the platform than to rotational movement of the platform and does not rotationally constrain the platform.

Abstract: The invention relates to a support device for the gun sight of a military vehicle, incorporating a head to which the gun sight is fastened and a foot which is integral with the vehicle, the head being integral with a column with a vertical axis which is introduced into the foot, the column being made integral with the foot by spring means wherein the spring means are constituted in the form of tongues arranged along at least two parallel planes perpendicular to the vertical axis of the support, each plane incorporating at least three tongues evenly spaced angularly around the column and integral with it by a first end and integral with the foot by their second end, these spring means imparting stiffness to the link between the column and the foot that is less along the vertical axis than along the other directions (X, Y) orthogonal to this vertical axis.

Abstract: A mounting assembly comprising an inner mounting sleeve having a cylindrical shank, wherein an end of the mounting sleeve is configured to be mounted to a support structure of a motorized device. The assembly comprises an inner grommet having a cylindrical shank, an axial opening of the inner grommet shank configured to accommodate the mounting sleeve shank there-through. The assembly comprises an outer ring sleeve having a cylindrical shank, the outer ring sleeve disposed around a portion of the inner grommet shank, the outer ring sleeve shank configured to accommodate an eyelet of a mounting arm there-around. The assembly comprises an outer grommet having a cylindrical shank, an axial opening of the outer grommet shank configured to accommodate the inner grommet shank there-in.

Abstract: A bicycle seat support that resiliently supports a bicycle seat and comprises an upper engagement member adapted to support a bicycle seat, a lower engagement member adapted to engage a bicycle frame, and a compliant support assembly coupling the upper engagement member to the lower engagement member. The compliant support assembly includes a first cantilevered beam cantilevered to the lower engagement member, and a second cantilevered beam cantilevered to the first cantilevered beam. The first and second cantilevered beams define a gap, and a resilient member is positioned in the gap. Preferably, the cantilevered beams include convex surfaces, and the resilient member includes concave surfaces shaped to receive the convex surfaces. The resilient member can include a body portion and a strut (e.g., two struts). The resilient member can also include a side surface and a recess in the side surface (e.g., extending all the way through the resilient member).

Abstract: A vibration damper, particularly for supporting compressors, pumps, electric motors and the like, comprising a flat body from which at least two engagement tabs protrude on each of the two faces and at least two elastically deformable contact and shock-absorbing portions protrude on at least one of the faces.

Abstract: An assemblage (8) comprises an electrical connector (10) having body (12) with a tubular projection (14) having a push-through portion (16) having a first diameter and an engaging portion (18) having a second diameter larger than the first diameter. A support (20) for the electrical connector (10) has a major part 22 that is substantially rigid and includes an aperture (24) formed by a plurality of deflectable spokes (26). The aperture (24) has a center opening (28) with a third diameter greater than the first diameter and less than the second diameter, whereby the tubular projection push-through portion (16) slides through the aperture (24) and the spokes (26) engage the second diameter of the engaging portion (18) and mount the electrical connector (10) with the support (20).

Abstract: The invention concerns mechanical retaining contacts (10) applied on a workpiece (4) placed on a substrate (1) by a double actuating mechanism (11, 42) which closes the circle of contacts (10) before lowering them onto the surface of the workpiece (4), thus ensuring a proper uniform contact. The contacts (10) may provide an electrical potential. The invention is applicable to electrolytic coating.

Abstract: The present invention pertains to extension arm apparatuses that are adapted to support user devices throughout a range of positions. A given apparatus may include one or more arms that position the user device remotely from a support position. An extension and retraction device such as a gas cylinder is received within each arm, and provides a force to support the user device as the arm is placed into a given position. A variable force clevis is connected to the extension/retraction device within the arm. The variable force clevis is connected to a pair of locations in the arm as well. As the arm moves, for instance up or down, the variable force clevis rotates within the arm and dynamically adjusts the force provided by the extension/retraction device. Removable and/or pivotable covers are provided for managing cables of the user device attached to the extension arm.

Abstract: A housing for mounting a collector plate comprises, in a preferred embodiment, a base with at least one concave recess, a plurality of clamps disposed about the periphery of the recess and an opening in a rear surface of the base. In a preferred embodiment, the clamps have plate-engaging surfaces which are biased toward the recess such as by springs.

Abstract: A net zero isolator having an elongated linear displacement member; and first and second counter rotation members arranged crosswise to the linear displacement member at either end thereof, each of the first and second counter rotation members including a mounting portion spaced apart from an isolated portion on respective first and second sides of the elongated linear displacement member. The elongated linear displacement member and the first and second counter rotation members are structured such that a displacement of the mounting portions along the linear displacement member is balanced by a displacement of the isolated pads. The net zero isolator acts through each of the first and second counter rotation members to generate displacements of the isolated portions that cancel a linear displacement of the mounting portions.

Abstract: A strain-isolated mirror is made from a substrate having first and second body portions. First and second connecting portions extend across a gap between the first body portion and the second body portion. A first flexural hinge on the first second connecting portion couples the second connecting portion to the first body portion.

Abstract: The portable air purifying device (10) is provided for removing airborne particles. The device includes a housing (12) including an exterior surface formed with an air inlet (26) and an air outlet (28). The air outlet is formed as a plurality of openings. A scroll (44) is located within the housing and has walls formed with an intake opening (194) and an exhaust port (186). The exterior surface and the walls define a cavity (76). The cavity has a first portion and a second portion. The first portion is in communication between the exhaust port and the air outlet. A fan (14) is positioned within the intake opening for drawing air in through the air inlet to pass through the scroll and the first portion of the cavity to be expelled through the air outlet while the second portion of the cavity is under a positive pressure. A filter assembly (48) is assembled within the housing between the air inlet and the fan. The device can include a second filter assembly.

Abstract: A housing for a motor is described. The housing extends between a pair of endshields and includes an inner surface, an outer surface, and at least one raised projection extending outwardly from at least one of the housing inner and outer surfaces. The projection includes at least one opening extending therethrough and at least one fastener configured to attach to the inner surface and extend outwardly through the housing opening.

Abstract: The invention concerns a launch vehicle comprising a shroud (1a, 5a) supporting auxiliary propellers (2, 3) applying in operation excess flow of stresses to the shroud (1a, 5a), said device comprising means for coupling the payload (4) with the launch vehicle shroud. The invention is characterized in that the coupling means are designed to ensure a mechanical coupling between the payload (4) and the shroud along the direction of the launch vehicle longitudinal axis (X), and to cause them to be disengaged along radial and tangential directions. The invention is useful for neutralizing the effects on the payload of excess stresses applied on the launch vehicle shroud by the auxiliary propellers (2, 3).

Abstract: A motor holder for holding a motor is provided. The motor holder includes a motor housing segment, a plurality of radial ribs and a venturi ring segment. The motor housing segment receives and supports the motor. The radial ribs extend radially outwardly from an outer peripheral surface of the motor housing segment. The venturi ring segment is connected to radially outer ends of the radial ribs and circumferentially surrounds the motor housing segment. The motor holder further includes a plurality of oblique ribs. Each one of the oblique ribs is arranged between and is connected to each adjacent two radial ribs. Furthermore, each one of the oblique ribs is oblique to a radial direction that extends from the motor housing segment.

Abstract: Two opposing, interactive, and flexible force fields, formed by a flexible, suspension belt, exist within a sphere on opposite sides of it's equatorial plane and are engaged with a cylindrical musical drum by stretching parts of said belt away from the inner wall of an annular frame, to which it is attached, attachment points occurring in the before mentioned equatorial plane, and further into their respective semi-spheres existing on both sides of said plane. A cylindrical musical drum is placed inside the annular frame in such a way that the curved cylindrical shell of the drum exists in both semi-spheres simultaneously and is in parallel relation with the curved wall of the annular frame. The attached belt is stretched and engages a drum circumferentially at a plurality of points on the outer body of the drum near lugs which are attached to it's cylindrical shell.

Abstract: In known retaining devices for electric motors, rotationally flexible retaining elements on the order of leaf springs are provided between a receiving housing and the electric motor and serve to decouple noise of the electric motor. The novel retaining device for an electric motor includes retaining elements that extend axially between a receiving housing and the motor housing. These retaining elements enable low-frequency decoupling below the frequencies to be decoupled; on the occurrence of natural resonance when the electric motor is turned on and off or there are shocks from outside, the torsional motion of the retaining elements is limited by stop elements. The retaining device is especially well suited to electric motors of blowers.

Abstract: The present invention relates to an arrangement for the vibration-isolating mounting of an electric motor (2) on a support part (6) via an essentially disk-shaped support element (12). The support element (12) has a motor-holding section (24) for connection to the electric motor (2) and a support-holding section (26) for connection to the support part (6), and the two holding sections (24, 26) are connected via elastic, web-like connecting pieces (28). The connecting pieces (28) are designed such that the two holding sections (24, 26) are elastically movable relative to each other three-dimensionally in all directions in space, specifically axially, radially and tangentially, over a certain movement play. The support element (12) has integrated stop means for the three-dimensional limiting of the elastic relative movements of the holding sections (24, 26) and/or an additional mass (110) to influence the vibration behavior.

Abstract: A lateral acceleration force isolator that forms a part of an attachment fitting for a payload, such as a spacecraft or satellite, and launch vehicle assembly. An upper portion of the isolator is designed to be attached to the payload and a lower portion is designed to be attached to a launch vehicle. Flexures are positioned in an array between the upper and lower portions to accommodate lateral displacement in the payload attachment fitting, thereby isolating lateral acceleration forces.

Abstract: A motor assembly, such as an evaporator fan for a refrigerator, has a motor, first and second mounting bracket segments, and monolithic and elastomeric first and second grommets. The motor housing has opposingly protruding first and second end bosses. Each grommet includes inner and outer ring portions joined together by spaced-apart and generally-radially-extending spoke portions. The inner ring portion is positioned on the corresponding end boss. The outer ring portion has a hub and a circumferential flange radially projecting form the hub. Each mounting bracket segment has an opening, wherein the hub is positioned in the corresponding opening and wherein the circumferential flange longitudinally abuts the corresponding mounting bracket segment.

Abstract: A device for supporting an electric motor driving a turbine, which is particularly applicable for heating and/or air conditioning equipment for a motor vehicle. The device comprises a casing which defines a housing for receiving an enclosure of the motor. The housing comprises a peripheral wall connected to a front wall. The peripheral wall is interrupted so as to define at least one channel for cooling the motor. The cooling channel is defined by two lateral walls, at least one of which is connected to the font wall by an inclined deflecting wall to facilitate the guidance of the flow of air for cooling the motor.

Abstract: The invention is directed to a stress-free support which includes two parts 1 and 2 having different linear thermal expansion coefficients. One part can, for example, be a mirror support made of Zerodur and the second part can be an aluminum support structure. A compensating stress-free support with flexure joints (121 to 126, 211 to 213, 214 to 216) increases the stiffness with respect to tilting. The stress-free support has a low weight and a low structural elevation. The entire arrangement is planar.

Abstract: A universal automotive alternator which comprises an alternator body, a front plate and an assemblage for attaching the front plate to the alternator body. A back plate is also provided. A structure is for securing the back plate to the alternator body. A facility is for mounting the front plate to a bracket on an engine. In some instances, a component is utilized for mounting the back plate to a bracket on the engine.

Abstract: A transmission mechanism is capable of effectively attenuating vibrations generated thereby during operation by converting vibrations into heat energy. The base plate is provided with a plurality of flexible connecting ribs and a plurality of substantially sectorial openings formed alternately around a motor base part for holding a motor and bearing parts for supporting the shafts of the gears. Each of the gears has a rim provided on its outer circumference with teeth, a hub and flexible arms connecting the rim to the hub. Vibrations generated by the motor and those generated by the gears strain the flexible connecting ribs of the base plate and the flexible arms of the gears, the strains of the flexible connecting ribs and the flexible arms are converted into heat energy in the end and the heat energy dissipates, so that the variations are attenuated and noise attributable to the vibrations is suppressed.

Abstract: The axial flow fan structure has an outer ring and an inner ring that establish an annular air passage. An odd-number of arms join the inner and outer rings together and at least one of the arms is skewed with respect to a radius of the annular air passage in order to reduce noise and vibration and to increase fan efficiency. Labyrinth air passages are provided between the fan and the outer ring to impede air blow-past and to improve further efficiency and noise reduction. Internal vanes are also provided to cool the fan-driving motor in which each of the vane members have at least two edges, the respective edges forming different angles relative to the axis of fan rotation.

Abstract: A motor mount for reducing vibration and noise associated with motor load imbalances. The mount includes a one-piece elastomeric support having a motor attachment portion from which a plurality of supporting legs extend. Prior to assembly, the amount has a planar configuration. In assembly, the motor attachment portion is positioned around and secured to the motor by a clamp. Brackets are provided to secure the legs to a base. The mount provides the motor with pivotal freedom of motion but prevents substantial vertical displacement of the motor. The motor mount is well suited for use in centrifuges and other apparatus in which load imbalances cause vibration. In one embodiment, the mount includes three legs so that, in assembly, the mount is tripod-like.

Abstract: An active dynamic seat has a base, an intermediate piece linked to the base and a seat part linked to the intermediate piece. The seat part can tilt in all lateral directions and is linked in an essentially fixed manner in the vertical direction to the intermediate piece. One or more restoring devices act on the seat part. The intermediate piece is fixed at its lower end to the base and is resilient in the vertical direction. In another embodiment of the invention, the seat part is linked to the intermediate piece by several spring strips distributed around the periphery of the seat part and of the intermediate piece.

Abstract: A system is described which utilizes two perpendicular four-bar linkages coupled by a common plate to provide a translational-free flexible suspension having two rotational degrees of freedom about a desired point. One of the four-bar linkages is secured to a stationary "ground" structure, and the other linkage is attached to the object to be supported, such as a mirror. In one embodiment, two links of each of the two four-bar linkages are constructed from spring steel flexure elements which are rigid in all directions except about the rotational axis. The flexure elements thus comprise "revolute joints". Because the flexure elements function as spring hinges, no friction is encountered when the suspension is displaced or "pivoted".

Abstract: A centrifugal air blower has a housing with an inlet side wall through which a circular air inlet is formed. A cylindrical electric drive motor coaxially extends through the inlet opening and is drivingly coupled to a centrifugal impeller rotatably disposed within the housing. The motor is supported on the inlet side wall by a mounting system including a plurality of metal mounting rods each having an inner end, an outer end, and an elongated intermediate portion. The inner rod ends are welded to circumferentially spaced locations of a belly band structure coaxially clamped to the drive motor, and the outer rod ends are connected to resilient support assemblies arranged in a circumferentially spaced array on the outer side of the housing inlet side wall around the blower inlet opening.

Abstract: It is an object of the present invention to control and damp with as few actuators as possible, vibrations generated in various directions on the bed of an automatic transport vehicle employed in clean rooms and other facilities. The automatic transport vehicle of the present invention comprises a truck (1a) and bed (1b) elastically supported with respect to the truck, a plurality of actuators (36) installed between them with inclined lines of action, sensors (40) which detect acceleration in the direction of the lines of action of these actuators, vibrations being suppressed by controlling the driving force of the actuators in accordance with the acceleration detected by the sensors.

Abstract: A double ended high intensity lamp holder of the type used in television and motion picture lighting applications is provided with an improved lamp holder for securely and safely supporting a double ended lamp. The improved fixture includes a pair of lamp holder assemblies each including a generally U-shaped lamp holder member with a spring clip thereon for quick and easy snap-fit reception of the opposite ends of a double ended lamp. The two lamp holder members are resiliently suspended by a spring mounting arrangement from a corresponding pair of support brackets, whereby the double ended lamp is resiliently mounted in a manner substantially isolating and protecting the lamp against damage due to thermal stress, physical shock, vibration, etc.

Abstract: An engine cooling fan assembly includes a mounting bracket having outwardly extending legs. A motor is mounted to a central hub of the mounting bracket. A multi-bladed fan is attached to and driven by the motor. A least one leg of the mounting bracket has a formed end with a ramp, a resilient grommet retained by a flange, and recesses between the ramp and grommet. A retainer is removably received on the end as barbs of the retainer are received and seated in the recess.

Abstract: A vibration-damping holding device for holding at least one pipeline having a holding body of a hard-elastic material and a receiving body of a soft-elastic material insertable into said holding body, the holding body having a lower part adapted to be anchored to a carrier plate, an upper part and resilient locking hooks for releasably connecting them to one another in a closed position, the upper and lower parts forming a cavity between them in the closed position for receiving the receiving body. The receiving body also has two parts that can be assembled together to form the body, each of the parts having an outer shell with an outer shape compatible with the cavity in the holding body and at least one semi-annular inner shell that cooperate as a pair with each other to hold a pipeline.

Abstract: A system for constraining a moving device to parallel plane translational movement, the system including a base; a frame fixed to the base and including frame portions disposed at the periphery of a region; a movable device disposed in the region; and a plurality of coupling elements connected between the frame portions and the movable device so as to provide support thereof, each of the coupling elements being capable of bending motion and incapable of twisting motion so as to guide movement of the movable device along a path including a series of planes all oriented substantially parallel to each other. The coupling elements restrict movement of the device to a desired sequential parallel plane path.