Abstract: A tire rim for a rolling apparatus with wheels mounted with a camber. The rim comprises a first shoulder having a first diameter, a second shoulder having a second diameter, and a main body arranged for connecting spoke elements, wherein the first diameter is larger than the second diameter. By having the first diameter of the first shoulder larger than the second diameter of the second shoulder the restrains of the tire at the first shoulder will be different than the restrains of the tire at the second shoulder. By mounting a wheel, comprising the tire rim according to the invention, with a camber, wherein the first and second shoulder have a substantially similar distance to the floor, the tire may be supported substantially more opposite to the floor.

Abstract: A caster mounting assembly for mounting a caster wheel on a wheelchair frame includes a mounting body defining a barrel portion to be fixed relative to the wheelchair frame and a rotatable body within the barrel portion that supports the caster wheel thereon for rotation relative to the rotatable body about an upright caster axis. The caster axis is arranged for rotation together with the rotatable body relative to the mounting body. A locking member is slidable within a channel in the mounting body and includes teeth in meshing engagement with corresponding teeth on the rotatable body. One or more positioning screws permit the locking member to be controllably displaced between longitudinally different locking positions within the channel corresponding to different angular orientations of the caster wheel axis.

Abstract: A movable wheelchair structure contains a base. A sliding mechanism is fixed on the base and includes two rods extending outward from one side of the base, with each rod including an auxiliary wheel extending outward from one end portion thereof. A vertical moving mechanism is fixed on the sliding mechanism. A frame is fixed on one side of the vertical moving mechanism and moves vertically and horizontally with the vertical moving mechanism and the sliding mechanism. A back support axially is coupled with a rear end of the frame. A leg member is axially connected with a front end of the frame. Thus, a user is capable of moving onto a bed or another position, enhancing usage at a hospital and at home.

Abstract: A sensor arrangement for a wheelchair wheel that has a running wheel with a hub and a hand rim includes a running wheel fastening arrangement that is fastened to the running wheel, a hand rim fastening arrangement that is fastened to the hand rim and at least one sensor that detects a movement of the hand rim fastening arrangement relative to the running wheel fastening arrangement. Two restoring elements are provided on the running wheel fastening arrangement and rest against the hand rim arrangement with a prestressing force at least in the zero position. Both restoring elements rest against at least one stop of the running wheel fastening arrangement in the zero position of the sensor arrangement.

Abstract: The present invention is a device which can be used to provide rotation motion to a driving wheel by the application of lateral motion by the user. It consists of axial track plate having a plurality of track paths with said guide paths having a plurality of slope sections. Additionally the caliper element can enable movement of a wheelchair's wheel from a first position to a second position. The caliper element is responsive to slope sections such that the slope sections can engage or disengage the caliper element. The caliper element's broad face is parallel to the track plate's broad face. The broad face is perpendicularly connected to each other via cylindrical pegs along the guide paths. The caliper element has a mating surface enabled to rotate a sprocket which is concentrically connected to a wheel hub where wheel rotates at the same angular velocity as the sprocket while the sprocket is in the engaged mode.

Abstract: A mounting assembly for attaching auxiliary equipment to a wheelchair includes multiple adjustment features. In the preferred embodiment, different wheelchair widths may be accommodated by utilizing attachment arms that pivot co-axially with a main column of the auxiliary equipment. The mounting assembly preferably includes a pair of arms and a pair of links that extend from the arms. The lengths of the links and the arms may be adjusted by rotation of a rod portion of each arm and each link, but other means for enabling changes in length are possible. The links are preferably pivotally connected to the arms, so that the distance between the ends can be varied on the basis of the particular wheelchair. Ball-and-socket joints are used, but rotatability of the sockets permits flexibility of the orientations of the joints. Additionally, a vernier adjustment effect may be included to permit adjustments in the angle of the main column.

Abstract: A seat for a wheelchair is provided. An exemplary embodiment of the seat includes a seat back portion, a bottom portion, and a linkage coupling the bottom portion to the seat back portion such that the seat back portion is movable relative to the bottom portion. The linkage generally includes a first link and a second link. The first link is generally pivotally connected to the bottom portion and the seat back portion. The second link is generally pivotally connected to the bottom portion and the seat back portion. The first link and the second link pivot relative to the seat back portion and the bottom portion as the seat back portion is moved relative to the bottom portion.

Abstract: A portable wheelchair is easily convertible between a conventional or street wheelchair and a specialty wheelchair through the use of conversion components, some of which are mounted permanently to the wheelchair and some of which are received by the mounted conversion components. In one form, the portable specialty wheelchair is a portable beach wheelchair while in another form the portable specialty wheelchair is an all-terrain wheelchair or trail chair. Preferably, but not necessarily, the portable convertible wheelchair is foldable in order to provide added versatility.

Abstract: A drive assistance device for a wheelchair includes a drive motor, a running wheel and a sensor device which is adapted to determine a driving force manually induced into the running wheel; and a control unit which is adapted to control the drive motor for driving the running wheel depending on the driving force manually induced by the user into the running wheel. The control unit of the drive assistance device includes a user force analysis operational mode which is adapted to determine data concerning physical efficiency and capacity of the user. These include a maximum force of the user as well as the maximum speed which can be reached with purely manual drive.

Abstract: A wheelchair has a car body of which rear and bottom wall portion are opened, a seat to be divided into right and left portions, a device for moving the right or left portion of the seat, and a holding plate provided on the car body for holding the device for moving the portion of the seat. The device has a link for connecting the seat portion to the car body, and an operation rod for operating the link so that the seat portion is moved between an opened position and a closed position, respectively. Wheels for supporting the car body, brake for the wheel, a brake operation device for operating the brake, a device is provided for synchronously driving the seat moving device and the brake operation device.

Abstract: A wheelchair includes a frame and first and second rear wheels that are each independently mounted to the frame via a respective mounting hub. Each rear wheel is detachably mounted to its respective mounting hub at two or more distinct hub mounting points. Either or both of the hub mounting points can be movable with respect to a remainder of the hub. A disk can be positioned at the rear wheel and a stop element located at the mounting hub can be selectively operated to interfere with the disk to prevent rotation of that rear wheel. Each rear wheel may include a push-rim having an elastomeric outer layer to facilitate manual gripping and an externally facing generally flat side face. The frame can include first and second spaced apart and unitary tubes which each extend in an unbroken manner from a wheelchair seat to a wheelchair forward region.

Abstract: A powered wheelchair includes a seat assembly configured to support an individual, a curved legrest assembly pivotally connected to the seat assembly, and an adjustment assembly including an actuator operatively connected to the central column through a piston slidably secured within a sleeve. The adjustment assembly is secured underneath the seat assembly. The powered wheelchair may also include an extension bracket that allows legrests and a central column of the curved legrest assembly to be separately and independently adjusted with respect to one another.

Abstract: An in-hub braking system for a wheelchair comprises a brake shell fixed against rotation movement in relation to a wheelchair frame. A wheelchair drive wheel having a hub supporting a braking system is supported for rotational movement in relation to the brake shell. A lever is operatively connected to the braking system for activating that braking system to cause the braking system to frictionally engage the brake shell. A push rim, which when urged forward, rotates the drive wheel in a forward direction to propel the wheelchair in a forward direction. When urged rearward together with the drive wheel, the push rim rotates with the drive wheel in a rearward direction to propel the wheelchair in a rearward direction. The push rim is operatively connected to the lever so that the push rim, which when urged rearward independent of the drive wheel, operates the lever to activate the braking system to frictionally engage the brake shell.

Abstract: Several new and useful concepts for a manually propelled vehicle such as a wheel chair are provided. In one concept, the vehicle is configured to be selectively placed in an automatic lock condition in which (i) the wheel chair can move in a conventional manner while an occupant is seated in the wheel chair, and (ii) the wheel chair is automatically locked against movement when an occupant begins to rise from a seated position on the wheel chair. In another concept, a particularly secure structure is provided for locking the wheel of the wheel chair against movement. In yet another concept, important components of the wheel chair are formed in a manner that facilitates assembly of those components into the wheel chair, by an internal fastening system and in a modular fashion.

Abstract: A mono-fork assembly for a front wheel of a wheelchair. The assembly includes a mono-fork member, an axle, and a retaining member. The mono-fork member has a single tine with a threaded aperture formed therein. The front wheel is rotatable on the axle. The axle has a distal end and a threaded proximal end. The proximal end is configured to be threaded into the threaded aperture of the tine and may be permanently bonded therein. A retaining member is coupled to the distal end of the axle to retain the front wheel on the distal end as the front wheel rotates about the axle. The mono-fork member may include a collar portion aligned along a steering axis for rotation thereabout. The mono-fork assembly may include a bumper configured to extend circumferentially about the collar portion within a circumferential groove formed in the collar portion.

Abstract: The present invention provides an ergonomic mobility chair comprising a frame, two primary wheels and at least one secondary load-bearing rolling point device. The primary wheels are usable for hand propulsion of the chair and positioned forward of the center of gravity of the chair. The primary wheels are mounted on a collapsible axle structure coupled to the frame. The at least one secondary load-bearing rolling point device is positioned aft of the center of gravity of the chair and coupled to the frame. A seat and two knee supports are coupled to the frame, the seat and the knee supports being arranged with respect to one another so as to position a user of the chair in a kneeling, upright, and generally neutral physiologic position. The seat and the knee supports each comprise at least a comfort cushion support coupled to the frame of the chair.

Abstract: Sloped-for-rain urban sidewalks are horrible for wheelchair users because of the constant veering-off threat caused by gravity. Anybody who tries to self-propel a wheelchair on a city sidewalk for the first time is in for a rude awakening—the user must use one hand to steer by retarding one wheel, and that makes propelling inefficient, difficult and frustrating, to say nothing of the dangerous veering-off threat. Applicant's solution (undiscovered heretofore (centuries)) is to provide joining means to couple and uncouple the drive wheels. The joining means, when coupled, causes the two drive wheels to rotate in unison preventing the wheelchair from veering-off so that it travels straight when traversing a sloped surface, and when uncoupled allowing the two drive wheels to rotate at different speeds to allow turning. Joining means comprises: slip-clutch, gear configuration or the like, and may be automatic or user controlled.

Abstract: A wheelchair comprising a frame, a seat assembly attached to the frame, two rear wheels attached to the frame, and at least one front wheel assembly attached to the frame. The frame defines a front face and two side faces. The front face is defined by one or more structural elements situated along a front of the frame, while the side faces are defined by two top side members and two corresponding bottom side members. The front face and the two side faces result in three non-orthogonal planes, which contribute to the strength and stiffness of the frame.

Abstract: A modular wheelchair assembly is adapted to be reconfigured between a fixed angle of tilt, a dynamically adjustable tilt-in-space configuration with the tilt axis being near the user's knees and a dynamically adjustable tilt-in-space configuration with the tilt axis being near the user's center of gravity. The reconfiguration is achieved by modifying a limited number of selectively removable components of the support assembly or the pivot assembly of the wheelchair.

Abstract: A wheelchair comprises a frame and first and second rear wheels that are each independently mounted to the frame via a respective mounting hub. Each rear wheel is detachably mounted to its respective mounting hub at two or more distinct hub mounting points. Either or both of the hub mounting points can be movable with respect to a remainder of the hub, for example via a pivoting arrangement. A disk can be positioned at the rear wheel and a stop element located at the mounting hub can be selectively operated to interfere with the disk to prevent rotation of that rear wheel. The frame can comprise first and second spaced apart and unitary tubes which each extending in an unbroken manner from a wheelchair seat to a wheelchair forward region.

Abstract: An architecture is presented that provides a riding platform device attachable to the back of a personal assistive mobility device, and more particularly to a removable and adjustable platform device for attachment to an electric or gas powered scooter that allows a companion to be transported along with the scooter and its driver, and thereby keep pace with an individual with limited mobility.

Abstract: A propulsion system for a manually-operated mobility device includes a hand rim configured to receive a propulsion force from a user of the manually-operated mobility device, a wheel hub fixedly attached to a wheel for the manually-operated mobility device, and a planetary gear system including a sun gear, a ring gear, and one or more planetary gears disposed between the sun gear and the ring gear. The one or more planetary gears are supported by a planet carrier. One of the sun gear and the ring gear is fixedly coupled to the hand rim and the other of the sun gear and the ring gear is fixedly coupled to the wheel hub.

Abstract: A wheelchair hand rim with mounting tabs and a resilient layer that provides for increased grip of and insulation from the core of the hand rim, and a method for making a wheelchair hand rim. The wheelchair hand rim may be provided with a variety of traction ring configurations.

Abstract: An automatic braking assembly and method are provided, where the automated braking assembly is formed as a complete unit, and is configured to be connected with a manually propelled vehicle. The automatic braking assembly that is formed as a complete unit includes (a) a housing, and (b) an automatic braking mechanism supported within the housing. The housing is configured to be connected with a portion of the vehicle to locate the automatic braking assembly in a predetermined position relative to a wheel of the vehicle, such that the automatic braking assembly will lock the wheel against movement when an occupant of the vehicle begins to rise from a seated position in the vehicle.

Abstract: A wheelchair chassis may include a first and second side frame positioned substantially parallel to and at a width apart from one another. The chassis may also include a first and second receiver tube positioned substantially parallel to and coupled to the first and second side frames, respectively. The chassis may additionally include a first and second extension tube telescopically engaged with the first and second receiver tubes, respectively. The chassis may further include a first and second cross member, with the first cross member pivotally coupled to the first receiver tube and the second extension tube and the second cross member pivotally coupled to the second receiver tube and the first extension tube. The second cross member may be engaged to the first cross member in an X-shaped configuration disposed horizontally between the side frames, where the second cross member is substantially co-planar with the first cross member.

Abstract: A wheelchair propulsion and contamination reduction arrangement permits the user to drive the chair on the main ground-engaging rear wheels with a compressible wheel cover that is grasped and squeezed against the wheel to provide propulsion and mounted with elastic tension devices on opposite ends that return the drive grip to a neutral position when the user relaxes the compression. The compressible device is a polymeric foam which can also be adapted to carry one or more of a lubricant, cleaner and biostatic treatment.

Abstract: A wheelchair comprises a main frame and a seat mounted on the main frame. A pair of front wheels and a pair of rear wheels are also mounted on the frame. A propulsion mechanism is provided for driving the rear wheels, the propulsion mechanism comprising an arm lever for forward and back movement and a gear train between the arm lever and the rear wheels.

Abstract: A mobility device including a frame, a plurality of wheels, a pair of telescopically arranged assemblies and a pair of handgrips. The plurality of wheels are rotatably coupled to the frame. The pair of telescopically arranged assemblies are coupled to the frame. The pair of handgrips are each coupled to a corresponding one of the pair of telescopically arranged assemblies. The pair of handgrips are arranged to adjust a height of the pair of telescopically arranged assemblies.

Abstract: Provided is a personal mobility device comprising a frame including two side structures. In one embodiment, main mobility wheels are coupled to ones of the side structures, the main mobility wheels configured to contact a surface upon which the mobility device is designed to move. In this embodiment, the mobility device further includes a knee rest rotatably coupleable to the frame, the knee rest being adjustable from a first substantially-vertical position to a second angled position, and further wherein the main mobility wheels are configured such that a kneeling occupant may propel the personal mobility device using the main mobility wheels.

Abstract: The back of a wheelchair user is independently supported along and about three mutually perpendicular axes. Two elongated adjustment arms are pivotally connected to extension arms which telescope into opposite ends of a hollow connecting tube. The support positions along and about the three axes is achieved by pivoting the arms and the connected relationships of a back shell and cushion to the connecting tube, while the adjustment arms remain pivotally connected to the wheelchair and the extension arms are telescopically retained in the connecting tube.

Abstract: A modular wheelchair assembly is adapted to be reconfigured between a fixed angle of tilt, a dynamically adjustable tilt-in-space configuration with the tilt axis being near the user's knees and a dynamically adjustable tilt-in-space configuration with the tilt axis being near the user's center of gravity. The reconfiguration is achieved by modifying a limited number of selectively removable components of the support assembly or the pivot assembly of the wheelchair.

Abstract: A wheelchair comprises a hub-enclosing open ring engaging a hub disposed in a wheel rotatably, bars extending from two ends of the hub-enclosing open ring, an crescent-shaped cap member fixed to the bars above the tube portion, a power handle engaging the crescent-shaped cap member rotatably through an L-shaped end of the power handle, a wheel-holding plate fixed to the power handle with an angle and covered by the crescent-shaped cap member. The wheel-holding plate comprises a holding edge for pressing down on and holding the wheel. The hub-enclosing open ring, the bars, and the cap member are fixed to one another and configured to rotate about the hub, and the holding edge of the wheel-holding pate is configured to be pressed down on and engaged firmly to the wheel such that the wheel rotates about the hub by pushing and pulling the power handle.

Abstract: A storage apparatus (10) attachable to a wheelchair (44) is pivotable and slidable from a storage position against the back of a wheelchair backrest to an access position adjacent to a wheelchair armrest. Pivoting and sliding is accomplished under power of an operator with the storage apparatus and slide mechanism (11) rotating substantially 90 degrees around vertical pivot member (30) and then sliding on a block member (18). A handle (24) is used to aide with the movement of the storage apparatus and to operate a locking mechanism (28), which secures the storage apparatus in access and storage positions.

Abstract: A mobility chair is arranged for a high degree of maneuverability, and is particularly useful for handicapped individuals in need of a highly stable and maneuverable carriage. The mobility chair may be particularly useful for children, and includes a seat positioned between first and second wheels of a first wheel set, wherein the axial spacing dimension of the first and second wheels is greater than the axle height. The mobility chair is arranged for pivotability about the first wheel set axle to permit the user to freely pivot forward while in the seat of the chair, with the pivoting being limited in both circumaxial directions about the axle axis.

Abstract: The disclosure relates to an assist device which can be coupled to a wheelchair.

Abstract: The invention relates to a wheelchair for example a wheelchair for an active user, a method of manufacturing a wheelchair and a wheel for a wheelchair. In further aspects the invention relates to a wheelchair, a footrest for a wheelchair, a wheelchair having a light, and a seat back for a wheelchair, a wheelchair that is water resistant.

Abstract: A wheelchair frame includes left and right first frame members, each having a first leg for supporting a seat. The first legs are arranged on opposite sides of a central axis of the wheelchair. At least one cross-brace is connected, by the ends, to the first legs of the left and right frame members. The cross-brace has a non-circular cross-section along a section between the ends. The wheelchair frame includes left and right second frame members that are pivotally connected to the left and right first frame members. The second frame members are foldable and may be fixed in a position in that is generally parallel to the first legs of the left and right first frame members. A cross-brace is connected, by the ends, to the left and right second frame members. The cross-brace has a non-circular cross-section along a section between the ends.

Abstract: The vehicle comprises a base and a seat moveable along a curve having a focal point. The vehicle is adjustable to position an occupant in the seat to achieve a desired position for the center of gravity of the occupant relative to the focal point of the curve. A method for minimizing effort required to tilt the seat of a personal mobility vehicle comprises the steps of providing a personal mobility vehicle having a seat that is adapted to move along an arc having a center of curvature, positioning the seat substantially horizontally, providing an occupant in the seat, and adjusting the position of the vehicle occupant's center of gravity so that the center of gravity is substantially equal to or below the center of curvature of the arc.

Abstract: A powered wheelchair includes a seat assembly configured to support an individual, a curved legrest assembly pivotally connected to the seat assembly, and an adjustment assembly including an actuator operatively connected to the central column through a piston slidably secured within a sleeve. The adjustment assembly is secured underneath the seat assembly. The powered wheelchair may also include an extension bracket that allows legrests and a central column of the curved legrest assembly to be separately and independently adjusted with respect to one another.

Abstract: A leg support assembly for use with a wheelchair is described herein. The wheelchair includes a frame, a seat assembly coupled to the frame, and a pair of legs extending outwardly from the frame. The pair of legs includes a first leg and a second leg spaced a distance from the first leg such that a gap is defined therebetween. The leg support assembly includes a support member that includes a first end that is removably coupled to the first leg and a second end that is removably coupled to the second leg. The support member also includes a flexible substrate material that extends across the leg gap to prevent a patient seated in the wheelchair from entering the gap. The leg support assembly also includes a fastening assembly that is coupled to the support member to facilitate coupling the support member to the wheelchair.

Abstract: A suspension seat comprises a structural layer and a stretchable top layer above the structural layer. The structural layer comprises a cut-out. The perimeter of the cut-out is defined by a plurality of discrete members. The discrete members allow the buttocks (i.e., the tissue surrounding the ischial sacrococcygeal aspects of the skeleton) of a wheelchair user to enter into the cut-out with gradual pressure minimizing high pressure concentrations at the edges of the cut-out. The stretchable top layer bears load via tension as the wheelchair user buttocks deflects into the cut-out.

Abstract: A wheelchair includes a frame, and a front pivot arm pivotally mounted to the frame at a front pivot point, the front pivot arm having a caster for supporting the frame. A rear pivot arm is pivotally mounted to the frame at a rear pivot point, the rear pivot arm having a caster for supporting the frame. A ground engaging mid-wheel drive wheel is connected to the frame. A linkage connects the front and rear pivot arms to each other in a manner such that an upward or downward rotation of one of the pivot arms about its pivot point causes rotation of the other pivot arm about its pivot point in an opposite rotational direction.

Abstract: A collapsible wheelchair (CW) may be relatively small and lightweight and may be adapted to be easily collapsed/folded into a callable faint, allowing for easy storage, transport and use. The CW may be adapted to be collapsed/folded and expanded/unfolded in a series of simple steps, executable with one hand, by a person in a seated position, allowing for independent use even by a user with limited physical capabilities. The CW may have a relatively small width, allowing for access into constricted spaces. The rear and interior space between its large wheels may be unobstructed, leaving an unobstructed inner width, allowing the CW to be maneuvered in reverse over standing objects, such as a standard toilet. The seat of the CW may be equipped with a trap door, to allow the use of a toilet while seated on the CW. The rim may be beneath the seat for cleanliness.

Abstract: A wheelchair for transportation of disabled includes a chassis and a plurality of wheels fixed to either end of chassis. At least one vertical support member is mounted at a predetermined location on the chassis to support a plurality of tubular fixator. A seat is joined to the tubular fixator which is pivoted onto the vertical support member and a plurality of friction knobs are provided on the tubular fixator to lock the horizontal and vertical movement of tubular fixator.

Abstract: A wheelchair includes a seat, one or more wheels and a seat weight sensing mechanism. The wheel includes a brake for stopping the wheel. The seat weight sensing mechanism is placed below the seat and is connected to the brake. When the seat is loaded by a weight more than a predetermined value, the seat weight sensing mechanism releases the brake to free the wheel. When the seat is not loaded by a weight more than a predetermined value, the brake stops the wheel.

Abstract: A wheelchair having torsion-acting shock absorbers from which cantilevered swing arms connected to drive wheels are connected is disclosed. The wheelchair incorporates a compact, collapsible power scooter that attaches to the wheelchair and presents a pair of handlebars having an accelerator and a brake, thus enabling the rider to propel him or herself by a power drive train rather than by hand.

Abstract: A telescoping crossbar assembly for a wheelchair comprises an inner tube that is slidable within an outer tube. The head portion of a pass-through fastener bears on the inner tube through a sufficiently large head-side aperture so as to slightly deform the inner tube and to hold the two tubes by friction in mutual engagement.

Abstract: A wheelchair system and an accessory system for a wheelchair are disclosed. According to one embodiment, the accessory system may include an accessory frame having one or more interface elements to mount to a wheelchair frame. The accessory system may include a wheel assembly rotatably coupled to the accessory frame by a first fastener. The accessory system may include an engagement system further coupling the accessory frame to the wheel assembly. The engagement system may include a channel guide member defining a channel having a notched region. The channel guide member may be rotatably coupled to one of the accessory frame or wheel assembly by a second fastener. The engagement system may further include a translating member retained within the channel of the channel guide member. The translating member may be fixed to another one of the accessory frame or wheel assembly.

Abstract: A reversible footrest includes an upper mounting device having attachment mechanisms mountable to either side of a wheelchair. An upper mounting device is connected to the lower mounting device which has a first support member that is capable of supporting a foot of a wheelchair user. A second mounting device having a support rod and supporting mechanism may be used to allow the reversible footrest to be raised or lowered. A second support member may also be used to support the lower leg of the wheelchair user. The attachment mechanisms and leg supporting components of the footrest are capable of being reversed to allow use on either side of the wheelchair.

Abstract: A transfer chair and a method of using the same. The transfer chair includes a base frame, a seat frame, and a seat having a front edge and a back edge and that is supported by the seat frame. A vertical lift mechanism couples the base frame to the seat frame and is configured to translate the seat from a first height to a second height. A seatback extends upwardly from the back edge of the seat in a first configuration and extends downwardly from the back edge of the seat in a second configuration. When the seatback is in the second configuration, a patient may slide over the back edge of the seat. A transition mechanism moves the seatback between the first and second configurations.