RELATED APPLICATIONS

This application claims the benefit of United States Provisional Patent Application No 61/200,598, filed December 1 , 2008, the content of which is incorporated heiein by reference m its entirety

TECHNICAL FIELD

The present invention is related to a versatile, collapsible cart-trailer with modular components More particularly, the present invention is related to a cart-trailer having a collapsible tow bar, collapsible handle, a tripod assembly, a castor assembly, a modular platfoπn and a modular accessory support system

BACKGROUND With environmental awaieness and the need to reduce our carbon footprint as a society, theie has been an mci easing need in transportation alternatives to driving One such alternative is that people are πding bicycles, are walking, or are taking public tiansportation However, when people are carrying or delivering goods, a device becomes necessary to facilitate carrying and delivery of the goods Conventional means for tiansportmg goods with a bicycle have been bicycle accessories mounted directly to the bicycle, which suffer from lack of volume and inadequate weight const amts Another conventional means for transporting goods with a bicycle is bicycle trailers Conventional means for transporting goods while walking, or via public transportation has been a cart In these conventional means, the conversion from cart to trailei and trailer to cart has not been possible Additionally, the conventional cart or tiailer has not been collapsible, or if foldable to an extent, still ietain a fairly large form factor Moieover, the means of carrying goods on these conventional carts oi trailers has been in a pre-defmed, constrained, non-compartmentalized space, which could not be changed by the user to accommodate various uses and forms of goods Furthermoie, the trailers are not conventionally configured for any veisatile bicycle, and the carts are conventionally not designed to be adjustable for the ergonomic needs of different users SUMMARY

In one aspect of the present invention, a universal multi -modal utility cart for transporting goods includes a folding mechanism that folds the utility cart into a small form factor, at least two wheels, and modular, removable and compartmentalized storage The utility cart is opeiable by multiple modes of transportation

In one embodiment, the utility cart includes a rigid frame and a modular accessory support system

In another embodiment, the folding mechanism automatically folds the modular accessory support system when folding the utility cart

In another embodiment, the modular accessory support system attaches to the storage, wherein the storage comprises modular baskets and the modular baskets click firmly into place onto the modulai accessory support system and are removable ftom the modular accessory support system with and without loaded goods In one embodiment, accessories coupling the storage to the frame are clipable onto the flame

In one embodiment, the folding mechanism includes a collapsible handle, a tripod assembly coupled to the collapsible handle comprising a length-adjustable vertical extrusion and a castor assembly, a foot pedal coupled to the tπpod assembly for disengaging a locking mechanism of the utility cart, and a hoπzontal platfoim foldable automatically and synchronously with the folding mechanism The collapsible handle initiates length adjustment of the vertical extrusion and folding of the utility cart, and the folding mechanism automatically collapses the at least two wheels, the castor assembly and the vertical extrusion such that the utility cart is folded into a form factor In another embodiment, the castor assembly comprises at least one wheel smaller than the at least two wheels

In one embodiment, the utility cart is operable via a cart mode

In one embodiment, the utility cart is operable in a tiailer mode by hitching the utility cart to a movable object In another embodiment, the movable object is a bicycle In another embodiment, the cart is hitched to the movable object using a collapsible and extendable tow bar In another embodiment, the tow bar is connected to the movable object by a hitch

In another embodiment, the tow bar is adjustable m length and telescoping In another embodiment, the tow bar includes a first telescopic channel, a first adjuster for adjusting a length and angle of the first telescopic channel and locking the first telescopic channel into place, a second telescopic channel, a second adjuster coupling the first telescopic channel to the second telescopic channel for adjusting a length and angle of the second telescopic channel and locking the second telescopic channel into place, and a third adjuster coupled to the second telescopic channel for adjusting a position of the tow bar The first telescopic channel is msertable into a hollow groove of the second telescopic channel.

In another embodiment, the storage includes loads of variable shapes and sizes.

In another aspect of the present invention a tow bar includes a fust telescopic channel, a first adjuster for adjusting a length and angle of the first telescopic channel and locking the first telescopic channel into place, a second telescopic channel, a second adjuster coupling the first telescopic channel to the second telescopic channel for adjusting a length and angle of the second telescopic channel and locking the second telescopic channel into place, and a third adjuster coupled to the second telescopic channel for adjusting a position of the tow bar. The first telescopic channel is msertable into a hollow groove of the second telescopic channel.

In anothei aspect of the present invention, a folding mechanism includes a collapsible handle, a tπpod assembly coupled to the collapsible handle comprising a length-adjustable vertical extrusion and a castor assembly, and at least two wheels coupled to the tripod assembly. The collapsible handle initiates length adjustment of the vertical extrusion and folding of the device, and the at least two wheels, the castor assembly and the vertical extrusion automatically collapse when the folding mechanism is engaged.

In one embodiment, the folding mechanism further includes a modular support system which is automatically collapsed when the folding mechanism is engaged In one embodiment, the folding mechanism further includes a foot pedal coupled to the tripod assembly for disengaging a locking mechanism of the folding mechanism

In one embodiment, the folding mechanism further includes a horizontal platform foldable automatically when the folding mechanism is engaged.

BRIEF DESCRIPTION OF DRAWINGS

The foregoing and other features and advantages of the invention will be apparent from the more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings m which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention

FIG 1 illustrates a perspective view of a system m accordance with an exemplary embodiment of the present invention.

FIG 2 illustrates a side view the system of FIG 1 m accordance with an exemplary embodiment of the present invention

FIG 3 illustrates a perspective view of a modular cart-trailer with a collapsible tow bar of FIG 1, in accordance with an exemplary embodiment of the present invention FIG 4 illustrates a perspective view of the collapsible tow bar of FIG. 1 m a fully extended state, m accordance with an exemplary embodiment of the present invention.

FIG 5 illustrates a perspective view of the collapsible tow bar of FIG 1 m a partially collapsed state, in accordance with an exemplary embodiment of the present invention.

FIG. 6 A illustrates a perspective view of the collapsible tow bar of FIG 1 m a fully collapsed state, in accordance with an exemplary embodiment of the present invention

FIG. 6B illustrates a perspective view of the collapsible tow bar of FIG 1 m a fully collapsed state, with horizontal telescopic channel nested into the vertical telescopic channel, in accordance with an exemplary embodiment of the present invention

FIG. 7 illustrates a perspective view of a modulai cart-ti ailer, in accordance with an exemplary embodiment of the piesent invention.

FIG. 8 illustrates a ieai, perspective view of a modulai cart-tiailer without any mounted components, in accoidance with an exemplaiy embodiment of the present invention.

FIG. 9A illustiates a perspective view of the modular cart-trailer of FIG 8 with a collapsed castor assembly, m accordance with an exemplaiy embodiment of the present invention.

FIG. 9B illustrates a perspective view of the modulai cart-trailer of FIG 9 A with a half rotated handle, in accordance with an exemplaiy embodiment of the present invention

FIG. 9C illustrates a perspective view of the modular cart-trailer of FIG 9B with a fully collapsed handle, m accordance with an exemplaiy embodiment of the present invention.

FIG. 9D illustiates a perspective view of the modular cart-trailer of FIG. 9C with a half collapsed vertical extrusion, m accordance with an exemplary embodiment of the present invention. FIG. 9E illustrates a perspective view of the modular cart-trailer of FIG 9D with a fully collapsed vertical extrusion, m accordance with an exemplary embodiment of the present invention

FIG. 10 illustrates a perspective view of a modular cart-trailer of FIG. 8 with a castor assembly in fully open position, in accordance with an exemplary embodiment of the present invention.

FIG. 1 1 illustrates a perspective view of a modular cart-trailer of FIG 10 with a castor assembly in a half collapsed position, m accordance with an exemplary embodiment of the present invention FIG. 12 illustrates a perspective view of a modular cart- trailer of FIG. 10 with a castor assembly in a three quarter collapsed position, m accordance with an exemplary embodiment of the present invention

FIG. 13 illustrates a bottom, close-up perspective view of the castor assembly of the modular cart-trailer of FIG 8, in accordance with an exemplary embodiment of the present invention

FIG 14 illustrates a close-up, perspective view of a modular platform, m accordance with an exemplary embodiment of the present invention.

FIG 15 illustrates a bottom, perspective view of the modular platform of FIG 14 mounted on top of the castor assembly, m accordance with an exemplary embodiment of the present invention.

FIG. 16 illustrates a perspective view of the modular platform of FIG 14 in a partially collapsed mode, m accordance with an exemplary embodiment of the present invention

FIG. 17 illustrates a perspective view of the modular platform of FIG. 14 in a fully collapsed mode, m accordance with an exemplary embodiment of the piesent invention FIG. 18 illustrates a close-up, perspective view of the modulai accessoiy support system, m accoidance with an exemplary embodiment of the present invention

FIG. 19A illustrates a close-up, perspective view of the modular accessory support system of FIG 17 with the accessory lower arm unattached, in accordance with an exemplary embodiment of the present invention. FIG. 19B illustrates a close-up, perspective view of the modular accessory support system of FIG 17 with the accessoiy lower ami stowed into the vertical extrusion, m accoidance with an exemplary embodiment of the present invention. FIG 19C illustrates a close-up, perspective view of the modular accessoiy support system of FIG 17 with the accessory lower arm stowed into a partially collapsed vertical extrusion, m accoidance with an exemplary embodiment of the piesent invention

FIG 2OA illustrates a close-up, perspective view of the modular accessory support system of FIG 17 with a modular basket unattached, m accordance with an exemplary embodiment of the present invention

FIG 2OB illustiates a close-up, perspective view of the modular accessory support system of FIG 17 with a modular basket attached, m accordance with an exemplaiy embodiment of the present invention FIG 21 A illustrates a perspective view of the modular cart-trailei of FIG 1 with the modular platform and accessory upper and lower arms attached, m accordance with an exemplary embodiment of the present invention

FIG 21B illustrates a perspective view of the modular cart- ti ail er of FIG 21 A with one modular basket attached to the accessoiy lower arm, m accordance with an exemplary embodiment of the present invention

FIG 21 C illustrates a perspective view of the modulai cart-trailer of FIG 21 A, with two modular baskets attached to the accessory lower arm, in accordance with an exemplary embodiment of the present invention

DETAILED DESCRIPTION

A modulai cart-tiailer 88 is usable as a cart, in a walking mode or via public transportation, as illustrated m FIG 7, as well as a trailer, in conjunction with a bicycle 12, a collapsible tow bai 84 and a universal hitch 80, as illustrated in FIG 1 The peispective view of FIG 1 and the side view of FIG 2 both illustrate the universal hitch 80 attached to a seat post 14 of the bicycle 12 The tear of the umveisal hitch 80 is connected to a collapsible tow bar 84, which is m turn attached to the modular cart-trailer 88 The universal hitch 80 may be a universal hitch such as the umveisal hitch described in United States Patent Application No 12/627,241, filed Novembei 30, 2009, the content of which is mcoipoiated herein by reference in its entirety FIG 3 illustrates the modular cart-trailer 88 m a cart mode One means for transforming the modular cart-trailer 88 from the modular cart mode to a modular trailer mode is to connect the modular cart-trailer 88 to the collapsible tow bar 84, which then hitches to the bicycle seat post 14, via the universal hitch 80, as illustrated in FIG 1 and FIG 2 The modular cart-trailer 88 may be converted fiom the trailei mode into the cart mode by disconnecting the collapsible tow bar 84 from the seat post 14 of the bicycle 12 and folding it alongside the vertical axis of the modular cart-trailer 88, as illustrated m FIG 3 Another means for transforming the modular cart-trailer 88 fiom the trailer mode into the cart mode is to disconnect the collapsible tow bar 84 from the modular cart-trailer 88, as illustrated in FIG 7 Thus, the collapsible tow bar 84 and universal hitch 80 components are not necessary for the modular cart-tiailer to operate in the cart mode, as illustrated in FIG 7

The modular cart-trailer 88 permits easy transformation fiom the trailer mode to the cart mode and vise versa In addition, the modular cart-trailer 88 is easily collapsible such that the modular cart-trailer 88 can be easily stowed away m, for example, a motor vehicle Specifically, the modular cart-trailer 88 can be stowed away in a motor vehicle by removing modular baskets 50, loading the modular baskets 50 into the motor vehicle, folding the utility cart, and loading the folded utility cart into the motor vehicle Further, the modular cart- trailer 88 permits for an increase in volume of goods that can be transported and permits for compartmentahzation of goods

The modular cart-trailei 88 may be used to tiansport and deliver goods or cargo of any kind The versatility of the modulai cart trailer 88 is due to a modular system of attachments, adjustable to form various configurations The modulai attachments may be simple baskets, bags, or any other specialized containeis or devices This enables the modular cart-trailer 88 to be versatile and seive many different usei needs FIG 3 and FIG 7 illustrate the perspective view of the modular cart-trailer 88, with two real wheels 40, a tnpod assembly 92, including a main collapsing mechanism, vertical extrusion 95, into which a modular system of attachments is mcoipoiated, a handle 60 to maneuvei the modular cart- tiailer 88 when in cart mode, and modular baskets 50, as an example of modular attachments Additionally, FIG 3 shows the collapsible tow bar 84 in collapsed mode along the tπpod chassis 90, as illustiated in FIG 8 The modular attachments aie illustrated as modulai baskets 50, however, the present invention is not limited thereto The modular baskets 50 may be bags or any other containers or devices The modular baskets 50 are removable from the modular cart-trailer 88 with or without goods In addition, the modular cart trailei 88 is described as having two wheels 40, however, the modular cart-trailer 88 may have additional wheels When the modular attachments, such as modular baskets 50, are removed, the modular cart-trailer 88 collapses into a very small form factor, as shown in FIG. 9E. A user initiates a folding mechanism with a foot pedal 94, as illustrated in FIGs 8 and 13 , which then causes all elements of the modular cart-trailer to collapse automatically, m a synchronous manner.

The modular cart-trailer 88 includes various components, namely, a collapsible tow bar 84, a collapsible handle 60, a tripod assembly 92, a castor assembly 115, a modular platform 120, and a modular accessoiy support system 52 Each of these components and the associated mechanisms are desciibed separately herein

The collapsible tow bar 84 is illustrated in a fully extended state m FIG 4, in a partially collapsed state m FIG. 5, and m a fully collapsed state m FIG. 6 A The collapsible tow bar 84 is of adjustable length m accordance with the size of the bicycle 12. The rear wheel diameter of the bicycle 12 may vary, resulting m a vertical clearance dimension that the collapsible tow bai 84 needs to clear, and a horizontally inclined distance from the bicycle seat post 14 past the iear wheel of the bicycle 12 and any lacks that may be attached on top of the iear wheel of the bicycle 12 that the collapsible tow bar needs to cleai As illustrated in FIG. 4, FIG. 5 and FIG 6A, the collapsible tow bar 84 includes two telescopic channels made from, for example, aluminum, namely, a horizontal telescopic channel 22 which is hollow and closed m its cross-section, and a vertical telescopic channel 24 which is hollow and open m its cioss section. A male poition 22A ol the horizontal telescopic channel 22 connects to a top angle and length adjuster 26 made of, foi example, stainless steel, aluminum and plastic parts, which are include internally a multi-toothed dog clutch The top angle length adjuster 26 enables rotation in an upward vertical direction and a downward vertical direction, enables the telescoping motion of the horizontal telescopic channel 22, and locks the horizontal telescopic channel 22 into place The multi-toothed dog clutch of the top angle length adjuster 26 is disengaged by pressing the top angle and length adjuster button 26A, and is engaged again when the top angle and length adjuster button 26A is released. Attached to the outei side of the top angle and length adjuster 26 is a universal hitch mount pm 34, which is keyed to be inserted into the corresponding ieceptacle in the universal hitch 80. Pressing the top angle and length adjuster button 26A enables adjusting the length of the horizontal telescopic channel 22, by sliding the male portion 22A of the horizontal telescopic channel 22 mto or out of the female portion 22B of the horizontal telescopic channel 22, and releasing the top angle and length adjuster button 26A locks it into place

The female portion 22B of the horizontal telescopic channel 22 connects to a middle angle and length adjuster 28 made of, for example, stainless steel, aluminum and plastic parts, which include internally a multi-toothed dog clutch The middle angle length adjuster 28 enables rotation in an upward vertical direction and a downward vertical direction, enables the telescoping motion of the vertical telescopic channel 24, and locks the vertical telescopic channel 24 into place The multi-toothed dog clutch of the middle angle length adjuster 28 is disengaged by pressing the middle angle and length adjuster button 28A, and is engaged again when the middle angle and length adjuster button 28A is released

A male portion 24A of the vertical telescopic channel 24 connects to a bottom angle adjuster 30 made of, for example, stainless steel, aluminum and plastic parts, including internally a multi-toothed dog clutch The bottom angle adjuster 30 enables rotation in an upward direction and a downward direction along its axis Unlike the top angle and length adjustei 26 and the middle angle and length adjuster 28, the bottom angle adjuster 30 does not enable the telescoping motion of any part of the collapsible tow bar 84 The multi -toothed dog clutch of the bottom angle adjuster 30 is disengaged by piessing the bottom angle adjuster button 30A, and is engaged again when the bottom angle adjustei button 30A is ieleased Piessmg the middle angle and length adjustei button 28A enables adjusting the length of the vertical telescopic channel 24 by sliding the female portion 24B of the horizontal telescopic channel 24 mto oi out of the male portion 24A of the horizontal telescopic channel 24, and releasing the middle angle and length adjustei button 28A locks it mto place

Attached to a rear side of the bottom angle adjuster 30 is a tow bar mount pm 32, which is inserted mto a corresponding tow bar mount receptacle 78 on the modular cai -trailer 88, as illustrated m FIG 8 The tow bar mount receptacle 78 includes internally a ball detent which enables rotation around its axis after clicking the tow bai mount pm 32 into place The female portion 24B of the vertical telescopic channel 24 connects to the downward side of the middle angle and length adjuster 28 FIG 4, FIG 5 and FIG 6A illustrate the gradual collapsing of the horizontal and vertical telescopic channels 22 and 24 using this telescoping adjustment mechanism described above, from a fully extended state m FIG 4, to a partially collapsed state in FIG 5, to a fully collapsed state m FIG 6A In FIG 5, the male portion 22A is partially slid into the female portion 22B and the male portion 24A is partially slid into the female portion 24B In FIG 6A, the male portion 22A is fully slid into the female portion 22B and the male portion 24A is fully slid into the female portion 24B By rotating the horizontal telescopic channel 22 downward towards the vertical telescopic channel 24, as illustrated with the rotational arrow m FIG 6A, the honzontal telescopic channel 22 may be fully inserted into the mside hollow groove of the vertical telescopic channel 24, as illustrated m FIG 6B

A method of installing the collapsible tow bar 84 onto the modular cart-trailer 88 is desciibed herein First, the tow bai mount pin 32 is installed into the tow bar mount ieceptacle 78 until the ball detent in the tow bai mount receptacle 78 clicks into place Second, the middle angle and length adjuster button 28A is pressed to disengage a locking mechanism and multi-toothed dog clutch of the middle angle and length adjuster 28 to simultaneously adjust the vertical telescopic channel 24 to a desned length and a desired angle The middle angle and length adjustei button 28A is released until the clutch teeth of the angle and length adjustei 28 fully engage and the locking mechanism locks into place Third, the top angle and length adjuster button 26A is piessed to disengage the multi -toothed dog clutch and locking mechanism of the angle and length adjuster 26 to simultaneously iotationally swing the universal hitch mount pin 34 to a desired angle and location and to adjust the length of the horizontal telescopic channel 22 The top angle and length adjuster button 26 A is released until the clutch teeth of the angle and length adjustei 26 fully engage and the length locks into place Fourth, the bottom angle adjuster button 30A is pressed to disengage a multi-toothed dog clutch ol the bottom angle adjuster 30 and change the angle of the collapsible tow bai 84 to a desned location The bottom angle adjuster button 30A is released and the angle is adjusted until the clutch teeth of the bottom angle adjuster 30 fully engage Fifth, the modular cart-trailei 88 is tilted and the universal hitch mount pm 34 is slid into the universal hitch 80 attached to the bicycle's seat post 14 until the ball detent m the universal hitch 80 clicks into place

A method for removing the collapsible tow bar 84 from the bicycle 12, and collapsing it onto the modular cart-trailer 88 along the tripod chassis 90 is described herein First, the top angle and length adjuster 26 is removed from the universal hitch 80 by sliding the ball retainer slide theieby releasing the ball detent holding the keyed universal hitch mount pin 34 in the top angle and length adjuster 26 Second, the top angle and length adjuster button 26A is pressed to simultaneously disengage the internal multi-toothed dog clutch of the angle and length adjuster 26, swing the keyed universal hitch mount pm 34 into the iecess in the horizontal telescopic channel 22, and collapse the length of the hoπzontal telescopic channel 22 down to the minimum length Third, the middle angle and length adjuster button 28A is pressed to disengage the internal multi-toothed dog clutch and rotate the hoπzontal telescopic channel 22 downward to the vertical telescopic channel 24 until it fully folds into a hollow groove of the vertical telescoping channel 24, while simultaneously adjusting vertical telescopic channel 24 to minimum length, as illustrated m FIG. 6B. The middle angle and length adjuster button 28 A is released and an angle is adjusted until the clutch teeth of the middle angle length adjuster 28A are fully engaged and the locking mechanism locks m place Fourth, the bottom angle adjuster button 3OA is pressed to disengage the internal multi- toothed dog clutch of the bottom angle adjuster 30 and change the angle of the collapsible tow bar 84 to be parallel with the tripod chassis 90, as illustrated in FIG. 3. The bottom angle adjuster button 30A is released and an angle is adjusted until the clutch teeth fully engage

The handle 60 is illustrated m FIGs 9A, 9B, and 9C in the fiontal perspective view of the modular cart-trailer 88 with the tripod assembly 92 in a fully collapsed mode The handle 60, illustrated m FIG 3, FIG 8, and FIG 9A, is made of, for example, aluminum encapsulated in foam, and is attached to the tripod chassis 90 at the top via a handle hinge 65. One function of the handle 60 is to enable a user to direct the motion of the modular cart- trailer 88 when used in the cart mode m an ergonomic manner A second function of the handle 60 is to host a variety of accessories on a hoπzontal handle accessory tray 62 to enhance a usei 's experience A third function of the handle 60 is to initiate the telescopic release of the vertical extrusion 95 for length adjustment or for folding the modular cart- trailer 88 As illustrated in FIG 9 A, the handle 60 includes a handle accessory tray 62 made of, for example, plastic, a front pull ring telescope release 64 made of, for example, plastic, and a rear pull ring handle release 66 made of, for example, plastic The handle accessory tray 62 may include a cup holder 67, a PDA holder 68, and a paper and pen holder 69 The rear pull ring handle release 66 is pulled m a grip fashion, to release the latch mechanism internal to the handle hinge 65, thus, allowing the user to fold the handle 60 up to an extended position to adjust the optimal angle for use The handle 60 can be locked in multiple positions between fully extended and fully collapsed, which is achieved by simply releasing the rear pull πng handle ielease and moving the handle to its next detent position FIG 9A illustrates the handle 60 in an open angle to the vertical extrusion 95 FIG 9B illustrates the handle 60 in semi-collapsed position FIG 9C illustrates the handle 60 in fully collapsed position

The tripod assembly 92 is illustrated m FIG 8 m a rear, perspective view, in FIG 10 in a fiontal, perspective view, and m FIG 13 m a bottom, close-up view The tπpod assembly 92 is comprised of several components and also connects to a castor assembly 1 15 A tripod chassis 90 made of, foi example, aluminum, nests a vertical extrusion 95 made of, for example, aluminum The vertical extrusion 95 telescopes m and out of the tripod chassis 90 to adjust the modular cart-tiailer 88 to a desired length during operation, or to collapse the modular cart-trailer 88 for storage A tripod uppei body 96 made of, for example, plastic, partially engulfs the tnpod chassis 90, and is attached to left and right rear wheel upper arms 97 made of, for example, aluminum or stainless steel The left and right rear wheel upper arms 97 connect to the left and right wheels 40, respectively From the bottom, the tnpod chassis 90 is attached to a tnpod collapse collar 110 made of, for example, plastic The tnpod collapse collar 110 connects to the castor assembly 1 15 via a castor wheel actuator 106 The tnpod collapse collar 1 10 is connected to the tπpod bottom cap 108, to the left and light ieai wheel middle ami 98, respectively, and left and right iear wheel bottom arms 99, lespectively The left and right rear wheel upper arms and the left and nght rear wheel bottom arms 99 are made of, for example, aluminum or stainless steel, and connect to the corresponding left and right iear wheels 40, respectively FIG 8 illustrates the foot pedal 94 and the tow bai mount receptacle 78 stemming from the rear side of the tnpod bottom cap 108

The castoi assembly 1 15, as illustrated in FIG 10 and in FIG 13, includes a castei arm hub 101 made of, foi example, aluminum, a caster mount 105 made of, for example, stainless steel, a caster wheel 100 made of, for example, a rubber tue and a plastic wheel, a caster upper ami 102 made of, foi example, plastic or aluminum, a caster lower arm 104 made of, for example, plastic or aluminum, a tnpod bottom cap 108 made of, for example, plastic or aluminum, a caster wheel actuator 106 made of, for example, stainless steel, and the tnpod chassis 90 The caster wheel 100 is coupled to the caster mount 105 with a horizontal pin creating a plain beanng The caster mount 105 is coupled to the castei arm hub 101 with a vertical pm and a thrust i oiler bearing element between the two The caster arm hub 101, caster lower arm 104, caster upper arm 102, and tripod bottom cap 108 are pinned together in a rotationally unconstiamed four-bar linkage. The caster upper arm 102 is connected to the tripod chassis 90 by the caster wheel actuator 106 The caster upper arm 102, the tripod chassis 90 and the caster wheel actuator 106 are fastened together by two horizontal pins

When the tπpod chassis 90 is moved m an upward direction (as illustiated m FIG 11 and FIG 12) the caster wheel actuator 106 pulls on the caster upper arm 102 to cause an upward swinging motion of the entne caster assembly 115. As the caster assembly 115 reaches its fully collapsed position, the caster wheel 100, guided by gravity, folds into a recess in the caster upper arm 102.

Collapsing the modular cart- trailer 88 to its smallest form factor, as illustrated m FIG 9E, requires several steps involving the tripod assembly 92, the handle 60 rotation, and the telescoping mechanism of the vertical extrusion 95 To initiate the tripod assembly 92 mechanism, the user lifts the foot pedal 94 illustrated m FIG 8 with their foot while holding handle 60 This causes the foot pedal 94 to disengage the internal locking features that secure the modular cart-trailer 88 in its open, non-collapsed position, as illustrated in FIG. 10 The usei continues to lift with their foot undei foot pedal 94, as well as lifting on the handle 60, which causes the entire modular cart-trailer 88 to be lifted slightly off the ground When this happens fπctional forces are reduced on the tues of the iear wheels 40, at which point an internal spring causes the wheels 40 to travel inwaids and the castor assembly 1 15 to move upwards beginning the collapsing process, of the tπpod assembly 92 mechanism. FIG 11 illustrates this step in a half-collapsed mode, and FIG. 12 illustrates a three-quarters collapsed mode The usei continues engaging this mechanism until the rear wheels 40, the castor assembly 1 15, and the tripod assembly 92, are completely collapsed, as illustrated m FIG 9A At this point an automated latch engages m the tripod chassis 90 to lock the unit m the closed position once the user's foot is lemoved from the foot pedal 94 The rear wheels 40 may then be placed back on the ground.

In a second step, the handle 60 is collapsed via its rotating mechanism as described and illustrated m connection with FIGs 9A, 9B, and 9C.

In a third step, the vertical extrusion 95 is collapsed fiom its fully extended position as illustrated in FIG 9C, to a half-collapsed position as illustrated in FIG 9D, to a fully collapsed position as illustrated in FIG 9E In FIG 9C, the user is presented with the front pull ring telescope release 64 in a more ergonomically ideal position The vertical extmsion 95 folding mechanism is engaged by pulling on the front pull ring telescope release 64, which releases the internal lock mechanism housed m the tripod upper body 96 Once this lock is released the user can adjust the height of the vertical extrusion 95 to any point in its travel, for example, as illustrated m FIG 9D, oi m a position fully stowed m its smallest collapsed form, as illustrated in FIG 9E The vertical extrusion 95 has a numbei of de-tented locations that it can be used in, which can be selected by ieleasmg the fiont pull ring telescope release 64 and then pushing or pulling the extrusion until it clicks into position

Reversing the steps for collapsing the modulai cait-tiailer 88 expands the modulai cart-tiailer 88 from totally collapsed form factor as illustrated m FIG 9E, to a fully expanded mode, as illustrated in FIG 10

The modular platform 120 is illustrated in FIG 14 in a close-up, perspective view without the full castor assembly 115, and is illustrated m FIG 15 m a bottom, perspective view mounted onto the full castor assembly 115 The modulai platfoπn 120 is a modulai element that may optionally be attached to the modular cart-tiailer 88 on top of the castor assembly 1 15 The exemplary function of the modular platform 120 is to hold and secuie optional loads The modular platform 120 is comprised of the platfoim center section 126 made of, for example, plastic, two platform outer wmgs 122 made of, foi example, plastic, two platform hinges 124 made of, foi example, plastic, two ielease plungers 128, and torsion actuation springs internal to the platform hinges 124 The underside of the platform outer wmgs 122 features bungee hook detents 130, as illustiated m FIG 15 One function of the bungee hook detents 130 is to attach veisatile load of geneiic sizes to the modular platform 115 via bungee cords The platform outei wmgs 122, platform hinges 124, and torsion actuation springs are attached to the platform center section 126 with platform hinge pins 125 made of, for example, steel, in four locations, as illustrated in FIG 14 The platform interlocks with the caster upper arm 102 to form a iigid assembly Due to the resulting rigid assembly, the modular platform 120 is made to automatically collapse upon initiation of the tripod assembly 92 collapsing mechanism

To initiate the tripod assembly 92 collapsing mechanism, as described above, the user lifts the foot pedal 94 illustrated m FIG 8 with then foot while holding handle 60, which causes the foot lever to disengage the internal locking featuies and initiate the collapse of the modular platform 120 via the uppei castor arms 102 When the upper caster arms 102 and suspension initiate collapse, ramped 'cam' features located on the top surface of the caster lower arms 104 contact mating cam surfaces on the ends of the platform release plungers 128 and force them to retract When the platform release plungers 128 letract, the platform hmges 124 and platform outer wings 122 simultaneously fold upwards and inwards due to forces from the internal torsion actuation springs, to close and he on top of the platform center section 126 This is illustrated in FIG 16 m which the platform outer wmgs 122 are in a half closed state, and m FIG 17 m which the modular platform 120 is m a hilly closed state with the platform outer wmgs 122 fully folded on top of the castor assembly 1 15

The modular platform 120 is not self deploying during the action of expanding the modular cart-trailer 88 To use the modulai platform 120 the user must manually unfold the two platform outer wmgs 122 by hand, by charging the internal torsion springs that deploy the wmgs The platform release plungers 128 on each side of the modular platform 120 automatically giab the platfoim outer wmgs 122 as they reach full deployment This is illustrated via the reverse sequence of the fully collapsed platform outer wmgs 122 illustrated m FIG 17, to the partially open platiorm outer wmgs 122 illustrated in FIG 16, to the fully open platform outer wmgs 122 illustrated m FIG 15

The modular accessory support system 52 is illustiated m FIG 18, and is intended to allow the modulai cart-trailei 88 to be peisonahzed to suit a number of different uses and tasks, ranging fiom the modular platform 120 with built-in bungee hook detents 130, described herein, to the modular baskets 50 as illustrated in FIGs 7, 21B, and 21C for caπying goods or shopping, to any number of other possible embodiments such as a laundiy hamper, pizza bag, and other such storage devices

The modular accessoiies are installed into the modular accessory system 52 via vertical extrusion holes 140, as illustrated in FIGs 18 and 19A The accessory lowei arm 144 is part of the modular accessory support system 52, and includes a narrow platform made of, for example, plastic, two accessory male mounts 146 made of, foi example, plastic, an accessory mounting block 143 made of, for example, plastic, and an accessory i el ease button 142 made of, for example, plastic To install the accessory lower arm 144 onto the modular accessory mounting system 52, the user holds the accessoiy lower arm 144 and aligns the end with the accessory mounting block 143 with a vertical extrusion hole 140 in the vertical extrusion 95 The user then rotates the accessory lower arm 144 arm and accessory mounting block 143 up to an angle of 45 degrees in order to enable insertion of an upper tongue of the accessory mounting block 143 into the vertical extrusion hole 140 in the vertical extrusion 95. Once the tongue of the accessory mounting block 143 is engaged, the user rotates the accessory mounting block 143 and accessory lower arm 144 back down to a horizontal position. At the horizontal location a pair of spπng loaded detents located mside the accessory mounting block 143 engage into two vertical grooves located on the inside face of the vertical extrusion 95, thereby locking the accessory mounting block 143 and accessory lower arm 144 in an attached and functional position.

The accessory lower arm 144 has two positions for use, deployed for use position, as is illustrated in FIGs. 18, 2OA, 2OB, 21 A, 21B, and 21 C, and the stowed position, as is illustrated in FIGs 19B and 19C, when inserted inside the inner cavity of the vertical extrusion 95. The user may set the accessory lower arm 144 in either position manually by simply lifting or lowering the accessory lowei arm 144 from a vertical to a hoπzontal position by simply engaging an internal ball detent latch at either end of the travel of the arm. The accessory lower arm 144 has the ability to automatically fold up into the cavity of the vertical extrusion 95 as the user initiates the collapsing of the vertical extrusion 95 into the tripod upper body 96 As the vertical extrusion 95 is extended, the accessory lower arm 144 will automatically deploy under light spring pressuie, cieated by an internal torsion spring in the accessory mounting block 143. Alternatively, the user may manually deploy or store the accessoiy lower arm 144

To remove the accessory lower arm 144 from the modular accessory mounting system

52, the user holds the accessoiy lower aπn 144 and accessory mounting block 143, while pressing the accessory release button 142 located on the back face of the accessory mounting block 143 and locked into a vertical extrusion hole 140 By pressing the accessory release button 142, a mechanism internal to the accessory mounting block retracts the two internal spring loaded ball detents that hold the accessory mounting block 143 inside the vertical extrusion hole 140. While piessmg the accessory release button 142, the user then rotates the accessory lower arm 144 and accessory mounting block 143 up to an angle of 45 degrees to allow the accessory lower arm 144 to be withdrawn in a linear fashion fiom the vertical extrusion hole 140 in the vertical extrusion 95. FIGs 2OA and 2OB illustrate an exemplary modular accessory, specifically a modular basket 50, comprised of a soft container made of, for example, fabric, hung fiom a horizontal basket accessory fiame 150 made of, for example, plastic, and two accessory female mounts 148 made of, for example, plastic The modular basket 50 is mounted onto the accessory lower arm 144 by pressing the accessory female mount 148 onto the accessory male mount 146, which then locks in place To dismount the modular basket 50 from the accessory lower arm 144, the usei presses inwards onto to the top of the protruding part of the accessory male mount 146, toward the center of the accessory lower arm 144, and simultaneously lifts the modular basket 50 by its basket accessory frame 150.

The system described herein for installation and removal of the accessory lower arm into and from the modular accessory support system 52, respectively, as well as for mounting and dismounting modular baskets, may be used for all modular accessories, such as the accessory upper arm 145, illustrated in FIG.s 21A, 21B, and 21C In FIG 21A, both an accessory lower arm 144 and an accessory upper arm 145 made of, foi example, plastic, are installed onto the vertical extrusion 95, but no baskets are mounted FIG 21 B illustrates this same configuration of the modular cart-trailer 88 with one modular basket 50 mounted onto the right side of the accessory lower arm 144. FIG 21 C illustrates this same configuration of the modular cart-trailer 88 with two modular baskets 50 mounted onto both sides of the accessory lower arm 144 FIG 7 illustrates this same configuration of the modular cart- trailer 88 with two modular baskets 50 mounted onto both sides of the accessory lower arm 144, and one modular basket 50 mounted onto the accessory upper arm 145.

While this invention has been particularly shown and described with iefeiences to preferred embodiments thereof, it will be understood to those skilled in the art that various changes in form and details may be made herein without departing from the spnit and scope of the invention as defined m the appended claims.