The invention relates to a method for the vertical semi-continuous direct chill casting of composite billets or plates comprising at least two layers of aluminum alloys, using a separator which is in contact with the solidification front and which provides a seal between the two alloys during casting, said separator being vibrated while it is in contact with the solidification front, so that the separator is not frozen in and entrained by the solid metal. The invention also relates to a device that can be used to carry out said method.

A method of casting a semi-liquid or semi-solid iron-based alloy, the method including: applying, to a part or to the whole of an uppermost surface of an inner surface of a die, a lubricating die-release agent in which particles including at least one selected from molybdenum disulfide, graphite, tungsten disulfide, boron nitride, chrome oxide and boric oxide are dispersed in a solvent; and thereafter casting by using the die.

A knitting machine includes a take-down assembly that includes a first take-down roller and a second take-down roller. The first take-down roller is configured to rotatably contact and apply tension to a first portion of a knit component. The second take-down roller is configured to rotatably contact and apply tension to a second portion of the knit component. The knitting machine further includes a first actuator that actuates to selectively adjust tension applied by the first take-down roller on the first portion of the knit component. Furthermore, the knitting machine includes a second actuator that actuates to selectively adjust tension applied by the second take-down roller on the second portion of the knit component. Additionally, the knitting machine includes a controller that is operably coupled to the first actuator and the second actuator to selectively and independently control actuation of the first actuator and the second actuator.

A knitting machine includes a take-down assembly that includes a first take-down roller and a second take-down roller. The first take-down roller is configured to rotatably contact and apply tension to a first portion of a knit component. The second take-down roller is configured to rotatably contact and apply tension to a second portion of the knit component. The knitting machine further includes a first actuator that actuates to selectively adjust tension applied by the first take-down roller on the first portion of the knit component. Furthermore, the knitting machine includes a second actuator that actuates to selectively adjust tension applied by the second take-down roller on the second portion of the knit component. Additionally, the knitting machine includes a controller that is operably coupled to the first actuator and the second actuator to selectively and independently control actuation of the first actuator and the second actuator.

A machine for the homogenization and thermal treatment of liquid and semi-liquid food products, for example ice creams, whipped cream, creams, chocolate, yogurt and the like, comprises a containment tank for the mixture and a centrifugal pump put in fluid communication with the bottom of the containment tank for drawing mixture from the tank and putting it back into the tank, heating and cooling means acting at the pump for heating and cooling the mixture in transit in the pump. The heating and cooling means comprise a thermal machine with reversible thermodynamic cycle and using carbon dioxide as refrigerant.

A container assembly (10) for retaining a liquid (16) during aging of the liquid (16) comprises a container (12) and an oxygenator (230). The container (12) includes a container body (14) that defines a chamber (14A) that receives and retains liquid (16). The oxygenator (230) is positioned substantially within the chamber (14A). The oxygenator (230) includes a fluid source (662), one or more diffusers (672), and a valve (670). The one or more diffusers (672) are in fluid communication with the fluid source (662). The valve (670) selectively controls the introduction of a fluid from the fluid source (662) into the liquid (16) through the one or more diffusers (672). The container assembly (10) further comprises an insert retainer assembly (338) and one or more flavor inserts (440) that are received and retained by the insert retainer assembly (338).

A grill is provided with a removable storage basket assembly for providing a conveniently accessible receptacle or storage platform for articles such as seasonings, cooking tools, towels, or other articles. The storage basket assembly includes a frame having a basket or tray that can be mounted thereto, and a handle. The handle is configured to be received within a recess formed in a shelf of the grill for removably but stably mounting the storage basket assembly on the grill.

A button assembly apparatus including a die assembly having two die members movable between an open and closed position. The die members include means for applying a covering on a button shell upon closing of the die members. Upon closing the die members a second time, selectively positionable means render the die members suitable for assembling the covered shell to a body member to complete the button.

Portions of a pin-on button are cut and assembled as a result of a plurality of operations in a machine having a vertical press. Cutter and work deforming tools are displaced by a single press ram to cut blanks and deform the blanks onto a button top placed in one of two die assemblies positioned in alignment below the work deforming tool on the lower end of the ram.

Apparatus for assembling covered buttons in which a first die assembly including a first punch carrying a first sleeve which sequentially receives a piece of covering material and the button shell with its flange extending toward the open end of the sleeve. A second assembly including a second sleeve having a bore one end of which is formed with a first cam surface extending axially inwardly of the above. The second sleeve is spring loaded to an extended position on a supporting post having a centrally located button back fastener receiving cavity in the end thereof with a second cam surface extending inwardly from the outer edge of the end to the bottom of a recess surrounding the cavity. An annular boss at the inner edge of the recess around the cavity is elevated to allow the material and the shell flange to curl inwardly under the button back. In the retracted position of the second sleeve on the post, the second cam surface forms a continuation of the first. In operation, when the first assembly carrying the covering piece and the shell moves toward the second assembly, the first sleeve stops against the spring loaded bottom sleeve and the punch continues forcing the material down so that the material is tucked inward by the beveled or curved surface of the second sleeve. Upon continued relative movement of the assemblies, the shell flange acts on the cam surface of the second sleeve to force the sleeve to its retracted position and the shell flange is moved inwardly of the back wall under the continued action of the first post, the extent of the inward movement of the shell flange being determined by the thickness of the material of the covering piece, as well as the height of the shell and the type of back used.

A device to assemble buttons of the type having a safety pin associated with a fastening member including an outer shell having a covering. The present invention is directed to the mechanism snap-out of the finished button and a cam and bar for automatically adjusting the length of travel of the upper die.

An improved method of forming and assembling two-part merchandise display hooks, including new design features of the hook itself, enable two-part hooks to be manufactured and assembled at extremely low cost. Wire from a continuous length is gripped and bent to form the outer portion of the hook. The wire is then severed and bent in a single operation to form a hook-mounting portion. While the severed wire remains gripped by its shaped outer end, a preoriented and guided base member is applied over the just-formed mounting portion of the wire. A retractable bend-forming member is withdrawn when the base member is applied to the wire, to enable the bent portion to be fully received within the plastic base. Major manufacturing economies are realized.

A method and apparatus for substantially automatically joining front and back parts of buttons employs a turntable with retaining means that are rotated through a series of stations at which the parts are placed in the retaining means in a desired orientation, joined, and checked for defects. A human operator places button front parts at a first station, and the remaining stations carry out the assembly and quality control steps automatically. Placement at the first station determines the alignment and orientation of the two buttons.

A universal assembly machine manufactures conventional buttons with formed backs. The machine comprises a rotatably indexable die table to which are mounted pickup and crimp dies. The die table indexes about a center column of the machine frame. A ram die is advancable and retractable in a pickup stroke and a crimp stroke by means of a handle. The ram die includes a ram outer ring that is rotatable by means of a shifter post joined to the die table. Indexing the die table causes the shifter post to rotate the ram outer ring into a pickup mode or a crimp mode to suit the ram pickup and crimp strokes, respectively. The universal assembly machine also manufactures buttons with flat backs by using a different crimp die pedestal than is used with the formed backs. An adapter on the crimp die pedestal used with formed backs allows that crimp die pedestal to also be used for manufacturing buttons with flat backs. The invention also embraces button medallions. A flat back button is loaded into the pickup die, and the die table is indexed. The ram die is advanced in a third press stroke to bend the shell frusto-conical wall of the flat back button inwardly to be flat and parallel to the flat back.

Hand pliers for assembly purposes includes an assembly limb and a handle limb rotatably connected to one another via a first link joint. The handle limb is divided into an off-handle lever and a handle-near lever and these two levers are rotatably connected to one another by a bolt via a second link joint, wherein a tension wheel and a ratchet wheel with external toothing connected torsionally proof to it are pivotably arranged on the bolt side by side in axial direction, and the tension wheel engages into a tension device that connects both handle limbs to one another, and a spring-loaded dog ratchet is arranged at the handle-near lever, engaging into the ratchet wheel in such a manner that when the handle-near lever makes a latching movement it permits a rotation of the ratchet wheel on closing the pliers, but prevents its rotation in the opposite direction.

An adaptor tool comprises a locking pin removably engaged with a main body defining a hook portion. The main body is configured to pivot about a pivot pin. The adaptor tool further includes a first link having first and second ends, and a first contact face. The first link is configured to receive the locking pin. A second link includes first and second ends, and a second contact face. The second link is pivotally coupled to the main body via the pivot pin. At least a third link includes first and second ends, and a third contact face. The first, second, and at least third links are pivotally coupled end-to-end such that the first, second, and third contact faces define a circular opening. The circular opening is configured to receive a workpiece such that rotational force applied to the main body rotates the adaptor tool and the workpiece.

A method for assembling a structure is described. The method includes locating a position in an assembly stack-up where a one-sided fastener is to be installed, drilling a hole through the assembly stack-up at the position, countersinking the hole to a specified depth, operating a calibrated probe to determine at least parameter associated with one or more of the hole and the stack-up proximate the hole, inserting the one-sided fastener into the hole, applying a rotational torque to the one-sided fastener to complete installation of the one-sided fastener, and comparing a measurement of angular displacement required to complete installation of the one-sided fastener to a range of angular displacement indicative of correct installation of the fastener.

A method for detaching a semiconductor chip from a foil uses a die ejector comprising plates having a straight supporting edge and an L-shaped supporting edge comprises: lifting of the plates to a height H1 above the surface of a cover plate;lowering of a first pair of plates with L-shaped supporting edge;optionally, lowering of a second pair of plates with L-shaped supporting edge;lifting of the plates that have not yet been lowered to a height H2>H1;staggered lowering of plates that have not yet been lowered, with at least one or several plates not being lowered;optionally, lowering of the plates that have not yet been lowered to a height H3

A process of controlling an actuating assembly for a coupling in the driveline of a motor vehicle, wherein the actuating assembly comprises a drive for moving an actuating element for operating the coupling unit, sensing a position signal representing the position of the actuating element; sensing a force signal representing the operating force required for displacing the actuating element; controlling the drive by means of an electronic control unit as a function of the position signal and the force signal. Further an actuating assembly is used for carrying out the process, as well as a drive assembly having such an actuating assembly.

Semi-autonomous vehicle apparatus which is controlled by a plurality of control sources includes a vehicle which may function autonomously and apparatus for control of the vehicle by either an onboard driver or a driver not situated onboard. The vehicle may also be controlled by an off-vehicle computational device. Hierarchy setting apparatus determines which of the possible control entities take priority. Persons using the apparatus are identified by either a password or, preferably by providing identification based on a biologic feature. Management of impaired vehicle operators is provided for.

Techniques for navigating semi-autonomous mobile robots are described. A semi-autonomous mobile robot moves within an environment to complete a task. A navigation server communicates with the robot and provides the robot information. The robot includes a navigation map of the environment, interaction information, and a security level. To complete the task, the robot transmits a route reservation request to the navigation server, the route reservation request including a priority for the task, a timeslot, and a route. The navigation server grants the route reservation if the task priority is higher than the task priorities of conflicting route reservation requests from other robots. As the robot moves within the environment, the robot detects an object and attempts to classify the detected object as belonging to an object category. The robot retrieves an interaction profile for the object, and interacts with the object according to the retrieved interaction profile.

A linear recliner assembly in use with a seat having a seat back pivotally engaged relative to a seat bottom. A housing exhibits a communicating interior between a first and second ends. A drive rod is supported in linearly displaceable fashion from the first end and is secured to the seat bottom. The second end pivotally engages the seatback spaced from its pivot point. A rotatable gear located at a fixed lineal position within the housing receives the drive rod in threadably inter-engaged fashion. A trigger mechanism pivotally secured to the housing exhibits a downwardly biased detent communicating through an opening in the housing to seat between succeeding teeth of the gear. A spring supported within the housing contacts the drive rod. Upon release of the detent, a reclining force applied to the seatback results in displacement of the housing against the drive rod to bias the spring. The spring influencing the drive rod in a reverse direction such that, upon release of said detent when the seatback is in the reclined position, the spring influences the seatback to reverse pivot to a returned upright position.

A patient side-system includes a column with a rail and a counterbalance subsystem. The patient side-system may further include a braking subsystem. The counterbalance subsystem includes a spring assembly coupled at one end to the column with a spring member, and a housing movably coupled to the rail. The housing includes a drum to receive the spring member and a plurality of roller elements to guide a movement of the spring member winding or unwinding on the drum. If present, the braking subsystem includes a first pulley rotatably coupled to the column, a second pulley with a locking mechanism spaced apart from the first pulley and rotatably coupled to the column, and at least one brake cable wrapped around the first pulley and the second pulley with ends coupled to the housing. The locking mechanism can set a position of the housing along the column.

A linear recliner assembly in use with a seat having a seat back pivotally engaged relative to a seat bottom. A housing exhibits a communicating interior between a first and second ends. A drive rod is supported in linearly displaceable fashion from the first end and is secured to the seat bottom. The second end pivotally engages the seatback spaced from its pivot point. A rotatable gear located at a fixed lineal position within the housing receives the drive rod in threadably inter-engaged fashion. A trigger mechanism pivotally secured to the housing exhibits a downwardly biased detent communicating through an opening in the housing to seat between succeeding teeth of the gear. A spring supported within the housing contacts the drive rod. Upon release of the detent, a reclining force applied to the seatback results in displacement of the housing against the drive rod to bias the spring. The spring influencing the drive rod in a reverse direction such that, upon release of said detent when the seatback is in the reclined position, the spring influences the seatback to reverse pivot to a returned upright position.

An assembly of a large format media handling system, including a planar longitudinal cross structure; and a support structure, the support structure including two side supports comprising a number of fixed references and at least one adjustable reference, wherein the side supports are supported by the longitudinal cross structure at said references; wherein the at least one adjustable reference is formed by a wedge element slidably attached to the support structure; and the side supports are fixed to the planar longitudinal cross structure wherein the cross structure is in contact with all of the references.

An assembly of a large format media handling system comprises a planar cross structure, and a support structure, the support structure including two side supports, wherein the two side supports extend perpendicularly to the cross structure and are connected to the cross structure at respective side edges of the side supports. A tensioning component is associated with each of the side supports, wherein the tensioning component transmits a tensioning force between the cross structure and the side edges of the side supports in a direction parallel to the side supports.

A retractable wheel assembly includes a bracing member and a wheeled arm pivotally coupled to the bracing member. The wheeled arm is sized and positioned such that the wheeled arm rotates through an aperture of the bracing member. The wheeled arm includes an arm member, a wheel, and an aperture cover shaped and positioned such that when the wheeled arm is in a retracted mode, the aperture cover covers a majority of the aperture, but not substantially all, thereby forming a wheel gap. The wheel assembly includes a deployment arm and a trap member operationally coupled to the deployment arm, including a trap flange sized and positioned to cover the wheel gap when in a closed mode and to substantially uncover the wheel gap in an open mode. The retractable wheel assembly includes a handle operationally coupled to the trap member.

A luggage assembly includes a first piece of luggage and a second piece of luggage. An attachment member is affixed to the second piece of luggage. The attachment member couples the second piece of luggage to the first piece of luggage so that the first and second pieces of luggage are self-stabilized while upright and inclined, and while in motion and while stationary.

An apparatus and method for forming a self-stabilized luggage assembly is disclosed. In one embodiment the method includes coupling a first piece of luggage in contact with a second piece of luggage using an adjustable stabilizer configured to couple a handle on the first piece of luggage to a handle on the second piece of luggage while wheels on the bottom of the first and second pieces of luggage remain on the ground when the first and second pieces of luggage are tilted, upright, moving, and stationary. Other embodiments are described and claimed.

The invention relates to a temperature sensor comprising: a temperature-sensitive element (3); and a peripheral casing (7) accommodating the temperature-sensitive element (3) and having a closed end (9), the peripheral casing (7) being able to be inserted into a corresponding cavity (11), characterized in that the closed end (9) of the peripheral casing (7) has a peripheral portion (21) revealing, butted against the closed end, a flexible assembly stop (23) after said peripheral portion (21), said stop (23) being able to deform towards the peripheral portion (21) by shape cooperation with the bottom (15) of the corresponding cavity (11). The subject of the invention is also a process for manufacturing a temperature sensor as described above and a method of assembling said sensor.

A mooring system, and connector assembly, which in a preferred embodiment is a vessel mooring and fluid transfer system. The connector assembly has a first portion (2A) configured to be coupled to one or more mooring lines (1), and a second portion (2B) configured to be coupled to a vessel. The first and second portions are rotatable with respect to one another to permit a vessel coupling on the second portion to swivel about the mooring coupling on the first portion. In a preferred embodiment, the connector assembly comprises a guide (2E) for a conduit, which may be a fluid transfer conduit such as flexible riser (6). The invention also provides methods of use of the mooring systems described.

A concealable fender assembly comprising a fender; a cover having an external surface form compatible with the lateral surface form of the boat hull in closed position; mechanism for actuating the cover for closing and opening thereof with respect to the boat hull lateral surface; wherein the cover is associated with the fender such that when the cover is in open position, the fender outwardly extends from boat hull lateral surface.

A craft includes a rigid hull (1) that consists of a V-shaped bottom (5) and a bridge (4) on which a load can rest. The hull includes plating consisting of compartmentalized pneumatic floats (2), the rear compartments (32) of which are combined with an inflation and deflation system so as to vary the buoyancy of the craft. The craft also includes a submergible hull (1), the central cavity (9) of which is formed between the bottom (5) and the bridge (4) and is open at the rear so as to be automatically filled or emptied, the central cavity (9) containing at least one bag (10) that is combined with an inflation and deflation system enabling the buoyancy to be varied and consequently the level of immersion of the stern (7) to be changed as needed.

An adaptor can convert a conventional hot air clothes dryer to draw air from outside instead of inside a building, and comprises an adaptor housing securable over the air intake region of the dryer in fluid communication with the air inlet of the dryer, with an adaptor housing inlet connectable to an air intake linkage. A filter and filter bypass assembly can be used in combination with the adaptor. The assembly comprises an outer enclosure and an inner enclosure inside the outer enclosure. An inner enclosure inlet and inner enclosure outlet define a first airflow path through the inner enclosure and an outer enclosure inlet and outer enclosure outlet define a second airflow path through the outer enclosure and bypassing the inner enclosure. The inner enclosure and the outer enclosure have a common aperture for insertion of a filter into the inner enclosure across the first airflow path.

A glove drying basket assembly holds gloves in a position maximizing air flow in and around the gloves to promote drying. The assembly includes a basket having a bottom wall and a perimeter wall extending upwardly from a perimeter edge of the bottom wall. A handle is coupled to the basket. At least one glove holder is coupled to the basket. The glove holder has a palm section and a plurality of finger sections coupled to and extending from the palm section. The glove holder also has an open bottom end and a plurality of openings in environmental communication with the open bottom end. The openings are positioned in spaced relationship over and around the palm section and each of the finger sections wherein the glove holder is configured to provide air flow to a palm and each finger of a glove positioned over the glove holder.

Press tool assemblies involve separable holder and tip portions. Self-seating structure is incorporated in these assemblies, and can stem from one or both of the separable portions of the assemblies. In use, the self-seating structure facilitates proper positioning and seating of the separable portions in relation to each other, and in some cases, can be used in operatively coupling the portions together. Advantages relating to assembly and disassembly of the tool assemblies, as well as improved structural properties result as a consequence of using the self-seating structure.

A substantially nitrocellulose-free insensitive gun propellant for barrel-type weapons is provided. The gun propellant includes at least one nitramine, such as HMX and/or RDX, a second energetic, and an inert binder system. The gun propellant is capable of producing a maximum projectile velocity exceeding 2680 ft/sec when fired from a 5 inch 54 caliber gun and gives a response to slow cook-off insensitive munitions testing of Type 4 or higher, and a response to fragment impact insensitive munitions testing of Type 3 or higher as measured by STANAG 4382 and STANAG 4496, respectively. Also provided is an ammunition round assembly, and an armament system.

Disclosed is a frame assembly including a framing member and an extrusion member. The frame assembly further includes a sheet having a graphic thereon. The sheet includes a gasket at a perimeter thereof, and the gasket is positioned in a channel of the extrusion member such that the channel supports the sheet.

A garment ironing assembly includes a panel that has a top side, a bottom side and a perimeter edge. The perimeter edge includes a front edge, a back edge, a first lateral edge and a second lateral edge. A pair of first extensions each is hingedly coupled to the bottom side. Each of the first extensions is selectively positionable and releasably retained in an extended position. One of the first extensions is extendable outwardly from the first lateral edge and one of the first extensions is extendable outwardly from the second lateral edge. Each of the first extensions is positioned adjacent to the front edge. Each of the first extensions is angled away from the front end when the first extensions are in the extended position. A support structure is attached to and extends downwardly from the bottom side of the panel to support the panel above a support surface.

An ironing board assembly includes an ironing board having a main board portion and at least one auxiliary board portion that is movably connected to the main board portion such that the auxiliary board portion is movable between operating and collapsed positions. A flexible ironing board cover is attachable to the ironing board so as to cover ironing sides of both the main and the auxiliary board portions, and to provide an ironing surface for a user to iron on. A tensioner is configured to pull the flexible cover taut over the covered ironing sides such that the ironing surface extends seamlessly across any joint or gap between the main and auxiliary board portions.

A composite hose includes a tubular body of flexible material for transferring cryogenic fluid through the hose and for preventing fluid leakage through the body. The tubular body includes an inner wire helix spirally wound along the length of the hose, an outer wire helix spirally wound along the length of the hose, at least two reinforcing layers placed in between the inner and outer wire, at least one sealing layer placed between two reinforcing layers, an end fitting at both ends of the tubular body, each end fitting provided with a part for connection to another hose flange and an elongated cylindrical part, which is divided in an anchoring area for anchoring the tubular body and a static sealing area for fluid tight sealing of the hose. A gas tight sealing is created by bonding the at least one sealing layer to the cylindrical part over a ring shaped bonding area.

A bearing casing assembly for a conveyor roller tube having a casing, a stub axle, bearings, an outer seal member and shield cap, is provided. The casing includes a body having a shoulder at its distal end extending circumferentially and radially outwardly for abutting against an end of the roller tube, an inner flange extending circumferentially and radially inwardly near the distal end from the casing body and an internally threaded a proximal end. The casing also includes a casing seat having a threaded portion for threadingly engaging the threaded proximal end portion of the casing body and a bearing engaging portion adapted to abut the bearing for selectively adjusting a preload on the bearing by rotating the casing seat about the casing body. The bearing casing assembly may further include an inner seal member when fluid lubricating bearings are used.

An inclined roller conveying assembly (40) includes a horizontally inclined roller (74) having opposite ends respectively supported by first and second supports (64, 66), with one support (64) having an idler bearing (80) and with the other support (66) having a drive coupling (94) that provides rotation of the inclined roller from a horizontal support and drive axis to provide support for the lower surface of an upper portion Gu of a hot upwardly concave formed glass sheet G being conveyed.

The present invention discloses a roller for conveying glass substrate. The roller includes a structure of roller body that is formed by assembling a plurality of roller components together in a disassembleable manner. An axle bore is formed in center of the roller. The present invention also discloses a roller axle assembly for conveying glass substrate, which includes a plurality of rollers and a roller axle. A distance is formed between adjacent ones of the rollers. Each of the plurality of rollers is individually disassembleable. The roller for conveying glass substrate and the roller axle assembly according to the present invention allows any one of the rollers that are mounted to a roller axle assembly to be disassembled individually thereby shortening the time period for replacing the glass substrate roller, increasing the utilization rate of the roller, and lowering down the device maintenance cost.

A rebuildable conveyor roller includes a hollow, cylindrical roller tube having a first end opposite a second end. The roller tube has a rebuildable conveyor roller bearing assembly provided at the first end and the second end. The rebuildable conveyor roller bearing assembly is affixed to the roller tube such that at least a part of the rebuildable conveyor roller bearing assembly is removable from the roller tube. A hub of the rebuildable conveyor roller bearing assembly has a generally circular shape that is dimensioned to fit inside the internal diameter of the roller tube. The hub has a centrally located hole through which a stub shaft may be inserted. A bearing holder is inserted in an internal cavity provided within the hub for securing the rebuildable conveyor roller bearing assembly to the roller tube.

Embodiments of the present invention provide a modular, portable, and adjustable wheelchair ramp that provides advantages and benefits over current wheelchair ramps. The ramp may be sold in a kit with individual elements, but it is also designed to provide a frame substructure that can be used with conventional decking materials, railings, and handrails.

A multi-directional roller assembly for directing articles in a conveying system. The multi-directional roller assembly has a rotatable roller frame housing at least one set of mutually-actuating rollers. The multi-directional roller assembly directs an article supported by the assembly along a trajectory determined by the orientation of the multi-directional roller assembly relative to an input force. The orientation of the multi-directional roller assembly may be changed to change the trajectory. A conveyor system may include an array of multi-directional roller assemblies. An actuator controls the orientation of the multi-directional roller assemblies individually and may also control an array of multi-directional roller assemblies as a group.