Abstract:
A wheeled cart includes a number of unique methods to synchronously stow all of the rear wheels of a fold flat, compact wheeled cart device without removing any of the wheels themselves and the innovations are applicable to cargo carriers, golf bag carts, trolleys, baby strollers, and other devices for moving cargo. In alternative designs, the folding motion of either the forward wheel frame, or the swiveling motion of the rear wheel frame, or both, synchronously setup or stow the cart&#39;s at least two rear wheels to achieve an ultra-thin stowed profile, orienting all the cart&#39;s wheels in a co-planar stowed relationship, closely parallel with all other parts.

Description:
RELATIONSHIP TO OTHER APPLICATIONS 
     This application relates to wheeled carts and carrier devices and particularly to wheeled cargo carrying devices, for transporting general cargo, luggage, golf bags, or for functioning as a baby stroller. Although this applicant has numerous previous patents within this field of art, this is not a continuation in part of any previous application by the inventor. 
     FIELD OF THE INVENTION 
     This application relates to fold flat, compact components for wheeled carts and provides for convenient, compact stowed orientation of at least three wheels on such carrier devices. Inventors in wheeled cargo carrying device carts continually strive to achieve compact, convenient stowed positions of the devices so that they take up very little storage space. One invention disclosed for cargo carrying devices provides that a rear wheel frame, with at least two rear wheels, swivels in relation to a forward frame—and the swiveling or rotating motion of the rear frame synchronously operates to fold and stow the two rear wheels of the device. Further, in the operative position most similar cart devices feature a forward frame and a wheel oriented perpendicular to a rear frame which rear frame includes a pair of rear wheels. In each embodiment of this invention, the forward frame moves into a stowed orientation, closely adjacent to, and parallel with, the rear frame. In this stowed configuration, at least one forward wheel and the rear frame wheels are linearly aligned occupying a co-planar relationship, and are all parallel with the rear and the forward frame together forming one combined side elevational profile of the over-all compact, stowed carrier. The innovations are applicable to carrier devices, golf bag carriers, baby strollers, carts, dollies, and trolleys, and the innovations provide for an ultra-thin compact stowed profile of the wheeled carrier device. 
     BACKGROUND OF THE INVENTION 
     Applicant&#39;s prior U.S. patents include, but are not limited to U.S. Pat. Nos. 8,720,912; 8,613,463; 8,544,871 and 8,500,140 among many others. Many of applicant&#39;s inventions seek to achieve compact stowed golf carts or baby stroller wheel designs so that the consumer may conveniently fold the device when not in use, and the products each achieve a compact stowed position. In the preferred embodiments of this particular invention, the device has a three-wheel orientation, and simple movement of both the front wheel, and of the at least two rear wheels, provides for folding and compacting of the wheels, without their removal, and results in the ultra-thin stored profile. In the above-mentioned previous U.S. Pat. No. 8,544,871, this inventor provided for synchronous folding of at least two rear wheels by virtue of at least one gear that synchronously caused movement and stowing of at least two rear wheels when a portion of the wheeled carrier device frame was folded. This application builds on the concept of synchronously folding at least two rear wheels of a wheeled carrier device, however; the synchronous folding of the at least two rear wheels is accomplished by either: 1) a unique swiveling motion of the rear wheel frame in relation to the forward wheel frame and/or the upper frame; or 2) the rotation of the forward frame in relation to the rear frame, however, unlike the foldable carrier devices of the prior art, this cart device achieves a stowed status of the forward and the rear wheels in a linear alignment, where each of the wheels&#39; axis of rotation are co-planar and closely adjacent to the rear, forward and upper frame stowed parts. Further, this invention does not have a gear which transfers the synchronous motion (like the applicant&#39;s prior art) but instead uses a series of linkages and connectors between the rear wheel frame and the other frame parts, and the rotation motion of the rear frame in relation to the remaining carrier parts is what provides for the synchronous folding and set up of the at least two rear wheels. 
     SUMMARY OF THE INVENTION 
     This application provides for compact, ultra-thin profiles for wheeled carts, such that none of the wheels need to be detached, but can be simply manipulated into an orientation which situates all the folded wheels axis of rotation into co-planar relationship with a forward and rear frame, conveniently providing for a compact device, and simple reversing movements of the wheels from their stowed position allows for their operative position set up. 
     One of the purposes of this invention is to provide for a forward frame and wheel that may be swept through an angle, into a compact orientation, closely adjacent to the rear wheel frame, and reversing motions allow for the setup of the same wheel. 
     One of the purposes of the invention is to provide for an extensible and retractable wheel arm for the forward wheel that is conveniently turned, and retracted into a compact forward wheel position, without wheel detachment. In a second embodiment, the forward wheel is not retracted, but is swept through an angle into a co-planar relationship with the device wheels. 
     Another purpose of the invention is to provide for a simple manually manipulable latch which allows for release of the operative position of the forward wheel, allowing it to be simply rotated along a guide channel so that the wheel may be easily stowed and can only be stowed by the user in one manner during the stowing motion. 
     Another object of the invention is to provide for a simple mounting bracket for a forward wheel of a carrier device, which provides a guide channel incorporated into the forward frame mounting bracket, to allow the extension and retraction of the forward wheel, and which provides a latching means within the mounting bracket for said forward wheel. 
     Another object of the invention is to provide that the mounting bracket on the forward wheel frame also includes cargo retaining means that are oriented into the mounting bracket of the forward wheel frame. 
     Another object of the invention is to provide for an upper frame of a wheeled carrier device that includes at least one upper stage in addition to a lower stage, which may be manually manipulated to various ergonomically advantageous positions to accommodate different height users. 
     Another object of the invention is to provide that the upper frame includes a handle grasp, and a portion of the upper frame, in the operative position, is retained to a portion of a lower frame by gravitational or resilient forces, and the same upper frame achieves a stowed compact position where the two upper frame stages become co-planar to one another in the collapsed state of the device. 
     Another object of the invention is to provide that the forward wheel frame includes a mounting bracket on which the rear wheel frame and at least two rear wheels are mounted. 
     Another object of the invention is to provide that at least two rear wheels and a rear mounting frame may be mounted to a forward wheel frame, and the rear wheel frame swivels or moves along an interconnection assembly (or a synchronous folding assembly) which facilitates motion that synchronously folds the rear wheels from an operative position to a fully stowed position where the rear two wheels, when stowed, are co-planar to each other and are parallel with the forward and the rear wheel frames, and a rear wheel frame finger grasp may be provided to facilitate easy swiveling of the rear wheel frame between the stowed and the operative positions. 
     Another object of the invention is that when the user manually moves either of the two rear wheels to achieve their stowed position, a series of linkages and joints synchronously sweep the position of each of the two rear wheels from the operative to the stowed position, and vice-versa, by the simple 90-degree swiveling or folding of the rear wheel frame, either clockwise, or counter-clockwise, in relation to the forward frame of the device to which it is movably secured. Similarly, another embodiment provides that the rotational motion of the forward frame in relation to the rear wheel frame provides the synchronous folding and unfolding of the rear wheels through a series of linkages between the said parts. 
     Another object of the invention is to provide for a rear wheel frame interconnection assembly, which is mounted to a portion of the front wheel frame mounting bracket, and the assembly has a series of linkages to a series of sliders mounted on the rear wheel frame, and the sliders further connect to a movable joint attached to each of the rear wheel axles, so that when the rear wheel frame is swiveled 90 degrees along the interconnection assembly securing point, it synchronously turns each of the two rear wheels, in tandem, from an operative wheel position perpendicular with the rear wheel frame to a stowed position wherein the two wheels and the entire rear wheel frame are substantially parallel with the rear wheel frame and closely contiguous to same, and reversing movements also synchronously move the rear wheels and the rear frame from the compact, stowed position to the fully operative, in use position. 
     Another purpose of the invention is to provide that the rear wheel frame interconnection assembly may be swiveled in a single direction, so that the user can only accomplish the folding, or the set up, of the rear wheel frame in the proper intended direction, or alternatively, the rear frame may instead be movable from an operative orientation perpendicular to the longitudinal direction of the forward frame, with the rear wheels in the operative status, to a rear frame stowed orientation co-planar and parallel to the forward frame, with the rear wheels folded closely adjacent the rear frame, aligning each rear wheel and the forward wheel&#39;s axis of rotation in alignment closely adjacent and along the longitudinal plane of the forward frame. 
     Another purpose of the invention is to provide that simple rotational movement of the forward wheel frame causes synchronous motion to be transferred by a series of linkages to rear wheels and the rear wheel frame, so that the folding motion of at least the forward frame and forward wheel in relation to the rear wheel frame, synchronously folds and stows the rear wheels, as well as the rear wheel frame, so that all wheels are co-planar and linearly aligned when stowed, closely adjacent to the forward frame, and in addition, closely adjacent to the upper frame forming a hand grasp. This and other portions of the innovations are further outlined in this application. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective of a carrier device, in accordance with one aspect of the present invention, in a fully operative position including a view of the forward frame, the rear frame, and the lower and upper stages of the upper frame, this figure, along with  FIG. 2  beside it, are the preferred cover drawing figures. 
         FIG. 2  is an underside plan view of the fully stowed carrier device of  FIG. 1  showing each of the frame parts in a parallel configuration and all of the stowed wheels in a co-planar configuration. 
         FIG. 3  is a slightly elevated view of the carrier device, similar to  FIG. 1  with the one change being the forward wheel has been released from its operative position and the movable wheel arm has been retracted along the forward frame toward the rear frame. 
         FIG. 4  is an end elevational view, slightly elevated, indicating that the upper and lower stages of the upper frame has been folded down into a configuration contiguous to, and parallel with, the forward wheel frame. 
         FIG. 5  is an underside view, cut away, of the forward wheel frame and the front wheel movable wheel arm including portions of the forward wheel mounting bracket. 
         FIG. 6  is an axial view along the front wheel movable wheel arm, cut away for a perspective, showing the front wheel bracket shaped guide path. 
         FIG. 7  is cut away side elevational view of the front wheel movable wheel arm, including the series of protrusions which interact with the front wheel bracket shaped guide path retraction and extension channel. 
         FIG. 8  is a view similar to  FIG. 5  except a latching portion of the front wheel movable wheel arm has been rotated 90 degrees out of a receiving portion of the front wheel mounting bracket, and a series of protrusions along the front wheel movable wheel arm are in alignment with a receiving channel forming a slide path or guide way. 
         FIG. 9  is an end elevational axial view of the front wheel mounting bracket, cut away for this depiction, also showing the latching protrusion that forms a part of the forward wheel movable wheel arm, allowing for its retraction, extension and securement along the front wheel frame. 
         FIG. 10  is a top plan view of the rear wheel frame and its swivel assembly, partly cut away to improve the view of the component parts, which parts cooperate to synchronously swivel in relation to the front device frame, and the swiveling provides for the stowing and/or setup of each of the two rear wheels and the rear frame in a synchronous manner. 
         FIG. 11  is an end elevational view of the rear wheel frame and component parts interconnecting the rear wheels with the swivel assembly which components synchronously provides for setup and folding of the rear wheels and the rear wheel frame. 
         FIG. 13  is an underside plan view of the rear wheel frame partially swiveled between the operative and stowed positions showing the swivel assembly components and each of the rear tires in an intermediate position, and showing the forward wheel in a fully stowed position. 
         FIG. 14  is underside plan view of the fully stowed carrier device with all wheels in their stowed positions, co-planar, and with the rear wheels and rear frame in a parallel configuration with the forward frame creating a thin stowed profile; 
         FIG. 15  is a bird&#39;s eye elevated view of simplified alternate wheeled cart device in accordance with another embodiment of the present invention, shown in a fully operative position; 
         FIG. 16  is also a bird&#39;s eye slightly elevated view of carrier device of  FIG. 15 , showing an intermediate folding position where the upper frame is in the beginning stage of the folding the unit toward the fully stowed position; 
         FIG. 17  is a side elevational profile view of  FIG. 15  showing the similar folded position as in  FIG. 16 , where the rear wheels have begun rotation toward the stowed position; 
         FIG. 18  is a side elevational view of the wheel carrier device of  FIG. 15  shown in the fully folded status, with all wheels of the device in a co-planar position; 
         FIG. 19  is a top plan view the wheel carrier device of  FIG. 15 , shown in the fully operative position; 
         FIG. 20  is a top plan view of the wheel carrier device of  FIG. 15 , shown in the beginning stages of the folding process towards the stowed position, showing an intermediate status of the rear wheels as well as of the front wheel; 
         FIG. 21  is a side elevational view of the carrier device of  FIG. 15  in the fully stowed position showing the co-planar view of the wheels of the device parallel with the frame portions; and 
         FIG. 22  is an underside plan view of the carrier device of  FIG. 15 , showing the folded frame portions. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawing figures the following are the description of the numbered elements:  100  carrier device cart embodiment;  101  simplified alternate carrier device cart embodiment;  1  forward frame;  1   a  front forward portion;  1   b  rear portion;  2  front wheel;  2   a  front wheel axle;  3  rear frame;  4  rear wheel;  4   a    4   b  rear wheel axels;  5  front frame cargo retaining means;  6  lower stage of upper frame;  7  upper stage, of upper frame;  7   a  upper frame connection joint;  7   b  upper frame adjustment means;  7   c  upper frame cargo retaining means;  11  forward frame arm;  7   d  push-pull handle grasp;  11   a  front wheel arm variation;  12  forward frame mounting bracket;  31  rear frame mourning arm;  32  rear frame mounting bracket;  32  aswivel assembly;  51  front wheel movable wheel arm;  51   a  front wheel fixing mount;  52  front wheel mounting bracket;  53  front wheel arm securing means;  54  manually manipulable latch;  55  latch resilient retaining means;  56  front wheel mounting bracket securing means;  311  rear frame wheel mount;  312  lateral plane of rear frame portion;  321  swivel assembly guide channel;  331  swivel assembly linkage;  332  rear frame slider;  333  rear wheel movable linkage;  334  rear wheel mounting axle;  335  wheel axis of rotation;  338  fixation member;  339  swivel assembly securing member;  340  rear frame swiveling finger grip;  341  movable parking brake;  342  upper to forward frame linkage;  343 A forward to rear frame linkage A;  343 B forward to rear frame linkage-B;  511  front wheel arm male-female guides;  521  front wheel bracket shaped guide channel;  521   a  front wheel bracket shaped guide latching channel;  521   b  front wheel mounting bracket movable wheel arm receiving means;  522  forward frame slider ring; and  523  side elevational profile. 
       FIG. 1  shows the preferred wheeled carrier device cart  100  in the fully operative position. In this preferred embodiment there is a single forward wheel and 2 rear wheels. It is appreciated that a different number of wheels may be utilized on the rear wheel frame or a double wheel configuration may be included on the forward wheel frame. The carrier includes a front wheel frame  1  to which at least a single forward wheel  2  is attached, which front wheel is mounted along a retractable and extensible movable wheel arm  51 , as explained below. The wheeled carrier includes a rear wheel frame  3  which is movably secured to the forward wheel frame bracket  12 , with a rear frame mounting bracket,  32  (shown more clearly in  FIG. 11 ). As explained in other figures, the rear wheel frame,  3 , is movably mounted to the underside of the forward wheel frame bracket  12  and the rear wheel frame includes a swiveling assembly  32 -A (see  FIGS. 10 and 11  for full detail) so that the rear wheel frame  3 , and the wheels  4 , for stowing purposes, swivel 90 degrees and the swivel motion synchronously also folds each of the rear wheels  4  into a compact figuration where the rear wheels and the rear wheel mounting frame  3  are stowed parallel with the other forward frame components and each wheel&#39;s axis of rotation  335  is also in a parallel configuration with the forward wheel frame. In the operative position, all of the carrier device wheels, and their axis of rotation, are orthogonal to the forward frame  1 . The device includes an upper frame  7  which includes a hand grasp (any suitable part of terminal portion of the upper stage  7  may serve as a handle gripping portion or portions), and may include 2 separate stages,  6  and  7 , and a manipulable joint  7 -A, which is secured and released by any suitable latching structure, shown as  7 -B. Any suitable cargo retaining means may be included as a part of the upper frame, here shown as  7 -C that may include a flexible strapping system although any securing means may be employed. Additionally it is noted that the upper frame is maintained in the upright position by a gravitational connection between a portion of the lower stage of the upper frame,  6 , and a portion of the rear wheel frame  3 , because the preferred upper frame position is inclined away from the center point of the device, and any suitable shape may be included on the lower stage of the upper frame in order to retain contact between the lowest portion of the lower stage of the upper frame and a portion of the rear wheel frame  3 . Any additional suitable cargo retaining means may be included along the forward wheel frame, for example as shown at  5 . This may take the form of any suitable protrusion or flexible fabric may be included to assist with retaining cargo, luggage or any other attachment that holds cargo or even a portion of a baby stroller inserted into a receiving portion of the device that may retain a child or baby. 
       FIG. 2  is a top plan view of the fully folded wheeled cargo carrier  100  where the upper frame parts, stages  6  and  7 , have been released and are folded flat in a parallel profile along with the forward wheel frame  1 , creating a single side elevational profile of the compact, stowed product. As shown in greater detail in other figures below, the forward wheel  2  mounted on the movable wheel arm  51  has been unlatched from its secured position, rotated along the fixed position forward frame arm  11 , preferably 90 degrees, and then by virtue of a series of guide way protrusions or recesses (see  FIGS. 5-7 ), the forward movable wheel arm  51  slides inside a guide channel  521  that is formed as a portion of the forward wheel mounting bracket  52  which permits retraction of the forward wheel  2  for stowing purposes. 
     As shown in further detail elsewhere, to achieve the fully stowed position shown in  FIG. 2 , the fully operative rear wheels and the rear wheel frame are swiveled preferably 90 degrees in a counterclockwise motion and this motion synchronously begins to turn each of the rear wheels  4  and the rear wheel frame  3  from a position perpendicular to the forward main frame, (not shown in this figure, shown more clearly in  FIG. 10 ) the wheels and the rear frame swivel begin to turn (see  FIGS. 12 and 13  showing intermediate swiveling positions) to the position parallel with the forward frame as shown in  FIG. 2 , where the rear frame and both rear wheels are co-planar with the forward wheel in a fully compact status of the device. 
       FIG. 3  is similar to  FIG. 1  except that the forward wheel  2  has been released from its secured position by virtue of the user manipulating a release latch  54  (See  FIG. 5 ) which allows the rotation of the forward wheel  2  preferably 90 degrees. Once the user turns the forward wheel 90 degrees, it may be retracted within and through a shaped guide path  521  formed as a part of the forward mounting bracket  52  and further along a shaped portion of the forward wheel frame that the preferably tubular forward movable wheel arm  51  then travels over (travels around and over a portion of the fixed forward wheel arm  11 ) to achieve the fully retracted stowed position shown here in  FIG. 3 . The details of the manner in which the forward wheel is released, and travels down a guide channel, to the fully stowed position, is detailed in  FIGS. 4-9  discussed later. 
     In  FIG. 4 , and in conjunction with  FIG. 3 , the wheeled carrier device  100  shows that the upper frame two stages have been released by using release latch  7 -B which releases the joint at  7 -A between the upper stage  7  and the lower stage  6  of the upper frame allowing the lower stage  6  to move downwardly in the direction of the forward wheel, and next in sequence the upper stage  7  folds to the collapsed status of the upper frame so that it is stowed parallel with and in the side elevational profile along with the forward wheel frame as shown in  FIG. 4 . 
       FIGS. 5-9  show the details of the mounting of the forward movable wheel arm  51  along the forward wheel frame  1  and the method by which the front wheel  2  is extensible and retractable. Referring first to  FIG. 5 , the forward wheel  2  is secured to the fixed wheel movable wheel arm  51  by virtue of a securing mount  51 -A. The forward wheel  2  is extensible and retractable along the fixed wheel movable wheel arm  51  which travels through a shaped guide  521  that forms a shaped opening portion of the front wheel mounting bracket  52 . The front wheel bracket  52  is secured to at least one shaped portion of the forward frame  1  by at least one front wheel mounting bracket fixing means,  52 -A. Also a portion of the forward frame mounting bracket  52  includes a shaped recess (Of course any suitable male/female system may be utilized; e.g., rather than a recess it may be a protrusion interaction with the front wheel arm  51 ). In this preferred embodiment of a latch, the latch  54  moves by means of resilient tension created by any suitable flexible material which resiliently retains the latch  54 , urging it towards the center point between the two forward arms  11  shown in  FIG. 5 . A manually manipulable portion of the latch,  54  is secured to a portion of the front wheel frame as shown at  55 . A portion of the fixed wheel movable arm  51  is retained in a suitable receiving portion of the front wheel mounting bracket  52  as shown at  53  in  FIG. 5 . When the user manually manipulates the latch  54  and frees the portion  53  connected to the front wheel movable arm  51  by rotating the front wheel 90 degrees, a series of protrusions,  511 , along an aligned plane along the movable wheel arm  51  are then oriented into an alignment that allows the front wheel movable wheel arm  51  to be retracted inward toward the center point of the device. There are at least two specially shaped portions of the forward frame mounting bracket  52  that permit the extension and retraction of the front wheel movable wheel arm  51 . 
     Referring to  FIG. 9 , the front wheel arm securing means  53  are shown in a secured position within a receiving portion of the forward frame mounting bracket  52 . Also  FIG. 9  shows the latch  54  and the securing means  56  and how a portion of the latch  54  retains the front wheel arm securing means  53  until the latch  54  is retracted, which allows this front wheel movable wheel arm  51  securing means  53  to be rotated preferably 90 degrees in preparation for retraction of the front wheel movable arm  51  also shown in  FIG. 9 . The front wheel movable arm  51  travels inside a shaped portion of the mounting bracket shown at  521 - a . A series of protrusions along the movable wheel arm  51  are noted as  511  in  FIG. 9  and are also clearly shown in  FIG. 5 . 
     A series of guide channels are shown in  FIGS. 6 and 7  that guide the extension/retraction and rotation of the movable forward wheel arm  51 . Once the forward wheel,  2  is released from its secured position and rotated 90 degrees the series of guide protrusions  511  must be oriented into alignment with the channel,  521 - b  as shown in  FIG. 7  in order to successfully retract the forward wheel movable arm  51 . After the rotation above mentioned, the movable wheel arm  51  is retracted through the shaped portion of the mounting bracket guide channel at  521 - a , and the series of protrusions  511  retain the front wheel  2  in the folded orientation as shown in  FIG. 4 . This retraction and extension orientation is shown in  FIG. 7  and prevents the user from accidentally or improperly turning the stowed wheel in any fashion except to retract it in the stowed position (it is appreciated that the system can be reversed and that there can be recesses along the movable wheel arm  51 , and protrusions may be formed in a guide way or guide path channel). In extending the forward wheel  2  from the stowed position the user can only move and extend the front wheel and the front wheel movable wheel arm  51  along the same plane the wheel was in when it retracted, to return it to the fully operative position and, in addition, the user cannot turn the front wheel 90 degrees back to the operational position until it is fully extended. The same channel and male/female protrusions that travel inside the channel  521 - a  prevent the forward wheel  2  from being placed in the operative position where it is orthogonal with the forward wheel frame until it is fully extended, at that point the movable wheel arm  51  is rotated which allows at least one protrusion  511  to rotate in the open shape  521 - b  which is isolated in  FIG. 6  and  FIG. 7 . Only when fully extended, can the wheel arm  51  be turned 90° and then a portion of that forward wheel movable arm, shown at  53 , rotates into the receiving channel  53  that further secures and latches the wheel  2  against unintended movement. 
       FIG. 10  is the first figure detailing a new state of the art innovation of the swiveling rear wheel frame  31  and the method by which a swivel assembly  32 -A permits both of the rear wheels and the rear frame  31  to be synchronously moved along the rear frame mounting bracket  32 , counterclockwise 90 degrees, to achieve a fully stowed position of the rear wheels. Referring to  FIG. 10 , the drawing shows a rear frame mounting bracket  32  which is movably secured to the front wheel frame mounting bracket  12  by virtue of a securing member  339 , which interconnects the rear frame  31  and the overall swivel assembly  32 -A to the bottom portion of the forward frame mounting bracket  12  (only partially shown in  FIG. 10 .) This rear frame mounting bracket  32  movable mounting method permits the entire rear wheel frame mount, including the at least two wheels  4  to swivel at least 90 degrees along the rotatable or swiveling mounting means  39 . Moving left and right from the central rear frame mounting bracket  32  in  FIG. 10 , a set of at least 2 swivel assembly linkages,  331  connected by securing means  338  to the mounting bracket  32 , and connected at the opposite end of the linkage  331  to a rear frame slider  332 , which sliders are slidably mounted along the rear frame  31 . Referring also to  FIG. 11 , the rear frame pair of sliders,  332  are further connected by a rear wheel movable linkage  333  which interconnects the slider  332  to the rear wheel mounting axle  334 . Each of the rear wheels  4  are mounted to the mounting axle  334  and then secured near the terminal end of the rear frame by a rear frame securing wheel mount  311 . 
     Referring to both  FIG. 10  and more particularly to  FIG. 11 , swiveling the rear frame  31  preferably 90 degrees, causes the swivel assembly linkage  331  to pull the slider  332  inwards toward the center point along the rear frame, and this synchronously also pulls inwards the rear wheel movable linkages  333  which are in turn also interconnected to the rear wheel axle  334 , to which the rear wheels are interconnected. Accordingly, as the rear frame is swiveled preferably 90 degrees, each of the rear wheels are thereby drawn in from the orthogonal position shown in  FIG. 11  to the intermediate positions shown sequentially in  FIG. 12 , and then  FIG. 13 , where each of the rear wheels  4  are partially moved inwards toward the center point of the rear frame  31 , and then to the completely stowed position showed in  FIG. 14 . In a completely stowed position, front wheel  2  and rear wheels  4  are linearly aligned with one another; and the front wheel axle  20  (axis of rotation) is parallel with both rear wheel axles  4   a  ,  4   b  (axis of rotation). 
     Additionally, as shown in  FIG. 10 , rather than manually grasping either wheel  4 , to move the rear wheels, the user may manually use a finger grip,  340  to assist in the rear frame swiveling motion to avoid the user having to actually handle or touch the wheel  4 .  FIG. 2  and  FIG. 14  show the fully compact stowed status of the wheeled carrier device whereby all of the wheels of the device are co-planar, closely contiguous to and parallel with the front wheel frame and the upper frame in its folded compact status. 
     Although previously explained, and referring to all the previous figures, in order to fold and stow the carrier device the user follows this order of steps: fold down the handle on to the forward frame, unlatch the front wheel, rotate it 90 degrees, move it inwards fully, and finally swivel the rear frame and wheels 90 degrees, preferably using the finger grip which synchronously moves both the rear frame and rear wheels to the stowed position. This motion orients the at least 3 device wheels in a co-planar orientation, and parallel with the forward wheel frame, and with the rear frame and the upper frame stages all parallel with each other forming a compact side elevational profile. To unfold, the steps above are reversed. In the compact fully stowed carrier device status, the three wheel&#39;s axis of rotation are oriented substantially below the forward and upper frame and are parallel with said frames, and each of said wheels axis of rotation are substantially aligned co-planar with each other. 
       FIG. 15  shows alternative foldable wheeled cart device  101  which is a more simplified embodiment of the carrier cart than device  100 . Device  101  attains many of the fully stowed features similar to device  100 , however, activation of the folding and unfolding process is accomplished differently. In embodiment  101 , movement of the forward frame 90 degrees in one latitudinal direction activates the synchronous folding of the rear wheels, whereas embodiment  100  instead retracts the front wheel and forward frame inwards towards the rear frame, and separate manual swiveling movement of the rear frame causes the synchronous folding of the rear wheels. Accordingly, in device  101 , latitudinally moving the forward frame in one 90 degree direction moves the at least one front wheel and the rear wheels into a co-planar folded profile, and reversed motion serves to setup the rear wheels and at least one front wheel. In cart device  101 , all the stowed wheels and their axis of rotation are co-planar and linearly aligned, closely adjacent to the front, rear and upper frames in a single side elevational profile. 
       FIG. 15  shows the carrier in the fully operative position showing a forward frame  1  to which at least one front wheel  2  is attached, as well as a rear frame mounting arm  31  to which rear wheels  4  are movably mounted. Although a different number of stages may be included,  FIG. 15  depicts an upper frame which includes a lower stage  6  and an upper stage  7  and the upper most terminal portion of the upper stage  7  forms a push/pull handle grasp. In alternative carrier  101  the series of linkages previously described in the application work similarly, but there are some differences, which can best be seen in the folding process shown in  FIG. 16 . As the stages of the handles  6  and  7 , forming a part of the upper frame, are folded in a forward direction toward the operative front wheel  2 , a series of linkages,  342  interconnect between the upper frame, lower stage  6 , and a forward frame slider ring  522 . The slider ring  522  is mounted around the periphery of the forward frame  1  and includes interconnected linkages between the forward frame  1  and the rear frame mounting arm  31 . 
     As seen in  FIG. 16 , as the upper frame handle folds forward, the multiple linkages  342  move a slider ring  522  along the upper frame, and one linkage between the slider ring interconnects to the rear frame mounting arm  31  as seen at linkage  343 A. A second linkage,  343 B connects between the forward frame sliding ring  522  and portions of the rear frame mounting arm  343 B. The aforesaid interconnected linkages force rotation of the forward frame  1  in a counter-clockwise direction (as depicted in  FIG. 16 ) ultimately rotating and swiveling the front wheel  2  to the fully stowed co-planar position with the other wheels of the device, as shown in  FIG. 18 , where the front wheel  2 , and each of the rear wheels  4  are folded co-planar and parallel with the frame mounting arm  31 . The front frame  1  and the two stages of the upper frame,  6  and  7 , are also in a parallel stowed configuration with the aforesaid wheels as shown in  FIG. 18 . Of course, alternatively the forward frame and the linkages can alternatively be organized to have the forward frame instead fold clockwise (not shown). Referring to  FIGS. 15-17 , these figures show how other linkages synchronously fold the rear wheels into their fully stowed configuration as well. As the front wheel  2  and the front frame  1 , move counter-clockwise during the folding process, as shown in  FIG. 15 , the linkage  343 A is interconnected, along the rear frame mounting arm  31  to a rear wheel movable linkage  333 . As the front frame and front wheel  2  move toward the fully stowed position by virtue of the movement of the upper frame stages  6  and  7 , this movement also pulls the linkage  343 A which is further interconnected to the rear wheel movable linkage  333  which synchronously folds one of the rear wheels between the operative position shown in  FIG. 15 , to the intermediate position shown in  FIG. 16 , and then fully folding it to the stowed position in  FIG. 18 . Likewise, the counter-clockwise folding motion of the forward frame  1  causes the other rear wheel  4  to fold in the following manner: a portion of the front frame  1  extends in a rearward direction past the transverse intersection with the rear frame mounting arm  31 . Another linkage  331 , mounted near the rear terminal portion of the front frame  1  links to a mounting slot along the rear frame mounting arm  31  (slot not shown in  FIG. 16 ). The linkage  331  is interconnected to a rear wheel movable linkage  333  which interconnects with the rear wheel  4  as shown in  FIG. 16 . As the counter-clockwise motion of the front frame moves from the operative to the stowed position, the counter-clockwise motion of the rear of the front frame pulls on the linkage  331 , and its interconnection to the rear wheel movable linkage  333 , which moves at least one rear wheel  4  from the operative position towards its stowed position as shown in  FIG. 18 . 
       FIG. 17  shows a side elevational view of the carrier  101 , providing a different perspective of the linkage from the upper frame  6  to the front frame  1  which is accomplished by a multiplicity of linkages  342  that are mounted to a slider ring  522  which is slidably mounted along the front frame  1 . As shown in  FIG. 17 , when the lower stage of the upper frame  6  is moved forward, and the linkage  342  slides toward the front wheel, the interaction of the series of linkages above explained, forces the rear wheels toward their stowed positions in a synchronous fashion and, the front wheel mounted on the forward frame  1  also folds from the forward position, counter-clockwise, towards the fully stowed position shown in  FIG. 18 . 
       FIG. 19  is a top plan view of the fully operative carrier device  101 , and the linkages can be seen more clearly here. Linkage  343 A connects the slider ring  522  to one of the rear wheel movable linkages  333  which interconnect with the rear wheel mounting axle  334  and the rear wheel  4 . In order to accomplish the innovation described in carrier  101 , the other side linkages are slightly different to accomplish the folding motion, and therefore  343 B interconnects between the forward frame slider ring  522  and portion of the rear wheel mounting arm  31 . 
     Referring to  FIG. 20 , which shows the intermediate folding position of the wheels, the front frame  1  is partially folded counter-clockwise towards the stowed position of the front wheel  2 . During this motion it can be seen that the linkage  343 A interconnects to the rear frame mounting arm  31  and to a rear frame linkage sliding member  332 , which is slidable along the rear frame mounting arm  31 . As the rear frame sliding member  332  pulls toward the center point of rear frame mounting arm  31 , it interconnects with the linkage  333  which serves to pull one of the two rear wheels  4  towards its stowed position.  FIG. 20  shows that on the other side of the rear frame mounting arm  31 , the interconnected linkages are slightly varied from the other side. The front frame  1  slider ring  522 , during the counter-clockwise folding motion of the front frame  1 , pulls forward toward the front wheel  2  and a linkage is connected to the slider along the front frame  1  at  343 B which connects to the rear frame mounting arm  31 . However, also as seen in  FIG. 20 , a rearward facing stub portion of the front frame  1  has another linkage at  331  connecting near the terminal rear end of the front frame, specifically to a sliding or recessed area along the rear of the rear frame mounting arm  31  (although the sliding recess is not shown clearly in  FIG. 20 ). The counter-clockwise motion of the rear portion of the front frame linkage  331  is interconnected with linkage  333 , which is further connected to the other rear wheel  4 , and as the front frame  1  is turned in the counter-clockwise motion, this causes the rear wheel  4  to move toward the fully stowed position which is shown in  FIG. 21 . 
     Referring to  FIGS. 19-22 , the movement between these figures demonstrates that the upper stage of the upper frame  7  has at least one joint connecting it to a lower stage of the upper frame  6  and referring back to  FIG. 16 , the intermediate position of the upper frame parts are shown at the beginning of the folding motion from the operative position towards the stowed position. In embodiment  101 , the joint between the lower and upper stages of the upper frame moves toward the front wheel mounting position, as the parts are folded, placing the fully folded upper frame connecting joint close to the stowed position of the front wheel  2 . The handle grasp of the upper stage  7 , is adjacent and contiguous to the rear wheels  4  when in the folded and stowed position. This can be seen more clearly in  FIGS. 21 and 22 . 
     To unfold the cart device  101  from the fully stowed position shown in  FIGS. 21 and 22 , the movement essentially is the reverse of that described above which accomplishes the unfolding synchronously, so that each of the wheels are moved from the fully stowed position shown in  FIGS. 21 and 22  to the fully operative position shown in  FIGS. 15 and 19 . In the stowed position e.g. ( FIGS. 21 and 22 ), the front wheel axis  20  and rear wheel axes  4   a  ,  4   b  are substantially parallel to each other and front wheel  2  and rear wheels  4  are substantially linear with each other. 
     It is appreciated that a different number of wheels may be utilized without departing from the spirit of this invention. It is also appreciated that the inwards movement of the forward wheel arm in embodiment  100  may take on various shapes and orientations (including other folding methods, rather than extending and retracting), or that this may be accomplished by tubular or rectangular shapes of the extension and retraction channel and arm. Also, any suitable latching method may be utilized to retain the forward wheel arm of embodiment  100  in its operative, or in the stowed compacted position, and a different latching method may be employed. With regard to the upper frame stages  6  and  7  of embodiment  100  it is appreciated that an extensible and retractable upper frame may be included, where a single plane is utilized and a portion of the frames extend and retract in a single plane, rather than two separate stages of the upper frame with a movable joint as disclosed in this application. Further, without departing from the innovation of the movable rear frame (in either embodiment  100  or  101 ) it is appreciated that different folding or motion methods may be employed that accomplish the main purpose of moving the rear frame and the at least two rear wheels to the alignment which moves the rear frame adjacent to the forward frame, parallel with the forward frame and which causes the rear wheels to be folded co-planar with the forward wheel, whether by swivel, rotation, or manual manipulation of the rear frame and the rear wheels one at a time rather than synchronously.