Abstract:
A cart assembly comprising a housing and a wheel assembly mounted in the housing, releasable locking means for selectively positioning said wheel assembly between operative and stored limit positions, a handle assembly and means for selectively positioning the handle between an outer operative limit position and an inner stored limit position inside the housing.

Description:
This application claims the benefit of U.S. Provisional Application Ser. No. 60/631,802 filed Nov. 30, 2004. 

   FIELD OF THE INVENTION 
   The present invention relates to improvements in cart assemblies characterized by novel features of construction and arrangement providing a cart which has collapsible and retractable features so that it can be easily positioned between operative and storage positions which is lightweight and has a bracing structure so that the cart can accommodate relatively heavy payloads. 
   BACKGROUND OF THE INVENTION 
   Carts are not new per se and are used for a variety of functions. For example, grocery carts and carts for handling luggage in airports are well known. Some of these carts have collapsible features even though they tend to be bulky and are often difficult to store in a relatively small space when not in use. Some of these carts are somewhat fragile and have a relatively small load-carrying capacity. 
   SUMMARY OF THE INVENTION 
   The features of the cart of the present invention make it eminently suited for use by shoppers frequenting large retail stores like Home Depot and Lowes. The compact and lightweight design makes it easy to store in a small space in the trunk of a car or in the rear compartment of an SUV. The handle can be released and locked in an operative position and the wheel assemblies pivot and lock in the use position easily and quickly at the parking lot. The items to be purchased can be easily loaded and secured on the cart. After checking out and loading, the items purchased in the car or SUV, the cart can again be easily and quickly stored for the next use by retracting the wheels and retracting the handle. 
   The cart is adapted for use by persons who show or train dogs. It has been found that space in vehicles such as SUV&#39;s, vans and trucks is at a premium because of the equipment needed at the show or training site, i.e. coolers, grooming equipment and other items. The cart of the present invention takes up little space in the vehicle and can be readily erected and loaded to transport what is needed from the parking area to the show or training site in one trip. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects of the present invention and the various features and details of the operation and construction thereof are hereinafter more fully set forth with reference to the accompanying drawings, wherein: 
       FIG. 1  is a perspective view of a cart assembly in accordance with the present invention in its operative position; 
       FIG. 2  is a perspective of the cart showing the wheels and handle retracted to facilitate storage of the cart assembly in a relatively small space; 
       FIG. 2   a  is an enlarged fragmentary view of the portion of the handle circled in  FIG. 2 . 
       FIG. 3  is a perspective view showing the cart in the retracted storage position as viewed from the underside; 
       FIG. 3   a  is an enlarged fragmentary view of the portion circled in  FIG. 3  labeled  3   a  showing a tab preventing pivoting of the swivel wheels when the wheels are retracted and nested in the top support cover; 
       FIG. 3   b  is an enlarged fragmentary view of the portion circled in  FIG. 3  labeled  3   b  showing the mechanism for locking the wheel assemblies in the retracted and operative positions; 
       FIG. 4  is a perspective view of the cart in the operative position as viewed from the bottom; 
       FIG. 5  is a perspective view of the cart in the storage position as viewed from the underside; 
       FIG. 5   a  is an enlarged fragmentary view of the portion circled in  FIG. 5  labeled  5   a  showing the locking lever pivoted to a release mode to permit rotation of the wheel assembly between limit positions; 
       FIGS. 6 and 6   a  are views similar to  FIGS. 5 and 5   a  respectively showing one of the wheel shafts rotated to a midway position; 
       FIGS. 7 and 7   a  are views similar to  FIGS. 6 and 6   a  respectively with one wheel assembly fully pivoted to an operative position wherein the lever is positioned to engage in a slot on a collar mounted on the wheel shaft to lock the wheel in this position; 
       FIGS. 8 and 8   a  show the spring biased locking lever automatically seating in the groove to lock the wheel assembly in the raised, operative position; 
       FIG. 8   b  is an enlarged fragmentary sectional view of the portion circled in  FIG. 8  showing the lever seated in a groove in a locking collar mounted on the wheel shaft; 
       FIG. 8   c  is a sectional view showing the complementary tapers on the lever and locking grooves to provide a rigid support when the wheels are at either limit position; 
       FIG. 9  is a fragmentary top plan view of the handle end of the cart; 
       FIG. 9   a  is an enlarged sectional view taken on lines A—A of  FIG. 9  showing the pin for locking the handle in an outer operative position and also showing the handle orientation pin engaged in a cut out in the handle pivot trunnion which aligns the handle angularly so that the locking pin can be inserted to lock the handle in the operative position; 
       FIG. 9   b  is a sectional view similar to  FIG. 9   a  with the handle in the operative outer position; 
       FIG. 9   c  is an enlarged fragmentary perspective view showing details of the swivel wheel mount and the handle orientation pin with the handle in the operative outer position; 
       FIG. 9   d  is a perspective view showing the handle in a stored position; 
       FIG. 10  is a side elevational view of the swivel wheel; 
       FIGS. 10   a  and  10   b  are sectional views taken on lines B—B and C—C of  FIG. 10 ; 
       FIG. 11  is a exploded perspective view of the cart assembly; 
       FIG. 12  is a fragmentary perspective view showing side and end panels which may be assembled rather easily and quickly to add side and end walls to the cart; and 
       FIGS. 13 and 14  are fragmentary perspective views showing the bayonet slots and buttons engaging in the slots to secure the panels at the corner locations. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings and particularly to  FIGS. 1–5   a  thereof, there is shown a multipurpose cart assembly in accordance with the present invention broadly designated by the letter C. 
   Considering first broadly the basic components of the Cart C and how they function, the cart comprises a top support cover C s  of generally rectangular shape having laterally extending cross braces B e  at the front and rear ends of the top support cover C s  and a middle cross brace B m  generally parallel to the end braces B e . A center brace B c  of inverted U-shaped cross section extends longitudinally from the front to the rear end of the cart generally transversely to the cross braces B e , B m . The particular shape and configuration of the various braces provides a relatively rigid construction so that the cart can support a payload of considerable weight. The top support C s  and braces are preferably made of a thin gage aluminum which can easily be stamped to the desired shapes shown and which have a pattern of screen mesh holes to provide a relatively light weight easily portable cart assembly. Enlarged openings O are provided in the side walls of the top support cover C s  so that objects can be secured to the cart by bungee cords anchored in the enlarged side wall openings O. 
   The cart assembly C includes a pair of front wheels W f  which swivel and a pair of fixed rear wheels Wr. The front and rear wheels as best illustrated in  FIGS. 4 and 11  are mounted on shafts Sw actuatable between a retracted position nested in the support cover (see  FIG. 3 ) and an operative position (see  FIG. 4 ). Means including a manually operable wheel release and lock lever L facilitates positioning the wheels in the stored and operative positions. 
   A handle assembly H is positionable between an operative outer limit position ( FIG. 1 ) providing a means to maneuver and guide the cart C and a storage position in a handle guide tube T h  located interiorly of the cart center brace Bc with only the hand grip portion exposed providing a means for carrying the cart C. 
   Considering now more specifically elements of the cart described above, the cart support cover Cs comprises a generally rectangular top panel  12  having depending side walls  14 , 14 , front and rear end walls  16   f  and  16   r  which in the present instance are formed integrally with the top panel  12 . The top panel  12  and support braces B are preferably made of a thin gage aluminum so that components of the cart such as the support cover Cs and the various braces B can be made rather economically by a stamping operation. The top panel has holes H in a predetermined pattern leaving solid portions in the region of the braces to accommodate screw fasteners for fastening the braces in place to the underside of the top panel  12 . The side walls  14  have a row of larger openings O to provide a means for latching a bungee cord to hold objects in place on the top panel of the cart. The side and end walls  14 ,  16  also have key hole slots  20  providing a means to detachably connect the side and end panels as shown in  FIG. 8 . 
   The bracing configuration to rigidify the top cover Cs to enhance the load carrying capacity of the cart C is best shown in the exploded perspective view of  FIG. 11 . As shown therein, there are two end braces Be, each of generally L-shaped cross section which are mounted adjacent the front end wall  16   f  and rear end wall  16   r . The upstanding wall  24  of each end brace Be has a scalloped cut out  26  to cradle the wheel shaft Sw in the manner shown. The middle brace Bm is of U-shaped cross section and has scalloped cut outs  32  at its outer terminal ends to accommodate the wheel shafts Sw. The center brace Bc also has a cut out  28  and mounts a center guide tube support  30  to accommodate mounting the handle guide tube Th. The upstanding side walls of the middle brace Bm have cut away portions to accommodate mounting of the handle guide tube Th. The center brace Bc is of inverted U-shaped cross section having spaced parallel depending side faces  40 ,  40  with outwardly directed flanges  44  to facilitate securing the center brace Bc in place by screw fasteners. The outer terminal ends of the center brace Bc are cut back as at  46  so that the terminal ends nest in slots  48  on either side of the center guide tube support  30  and the center brace Bc overlies and encapsulates the handle guide tube Th. 
   The elongated tubular shafts S for the wheels Wf, Wr are rotatably journaled at their outer axial ends in trunnion pivot support members  50  mounted on the upstanding faces of the end brackets Be in the region of the scalloped cut outs  28 . The front swivel wheels Ws are mounted adjacent the front end of the cart by a collar  52  held in a predetermined fixed position on the wheel shaft S and a swivel wheel holder  54  rotatably mounted on the collar. The fixed rear wheels Wr are mounted in a rigid caster mount  56  supported on the opposite end of the wheel shaft Sw in a predetermined position. 
   The system for controlling selective positioning of the wheel assemblies between an extended operative position and a retracted storage mode is best illustrated in  FIGS. 8   b . As shown therein the wheel shafts Sw are journaled in center support bearing  60  mounted in center brace Bc between a space collar  62  and a tubular pivot rod catch  64  having a series of circumferentially spaced locking slots  66  extending axially of the wheel shaft S w  which have tapered side walls  67 . A wheel release/lock lever  68  is pivotally mounted in an extended portion of the support bearing  60  by a spring  69  and is normally biased in a direction to pivot the tip  70  of the lever  68  to engage in the slots  64 . The tip  70  of the lever  68  has tapered side faces  72  complementing the taper  67  of slots  66  to snugly engage the slot and provide a rigid, wobble-free support for the wheels in the operative and stored positions. 
   The details and arrangement of the retractable handle assembly T h  are best illustrated in  FIGS. 9   a ,  9   b ,  9   c  and  9   d . The handle assembly comprises an elongated tubular shaft  100  of a hand grip P 102 , the shaft  100  is of a diameter less then the diameter of the guide tube for easy sliding movement when positioning the handle H between and an outer operative limit position (see  FIGS. 1 ,  9   b ) and an inner stored position (See  FIGS. 2 ,  2   a  and  9   a ). A handle pivot mount  104  seats in the open inner end of the handle shaft  100  which is pivotally connected at  106  with handle pivot attachment rod  108 . The rod  108  engages in the bore  110  of handle pivot trunnion  112  which projects through an enlarged window  114  in the front end wall  14  of the top support C s  for limited angular movement of pivot trunnion  112  and handle H to allow maneuvering of the cart by the user. 
   The outer end of the tubular portion  112   a  of the pivot trunnion  112  has aligned radial guide holes  118  for a locking pin  120  which can be inserted when the radial guide holes  118  are aligned with a radial through port in the pivot trunnion  112  as shown in  FIG. 9   a . The inner axial end of the handle pivot attachment rod  108  had a radially outwardly directed flange  108   a  which abuts the inner axial end face of the handle pivot trunnion  112  when the handle is withdrawn to its outer limit position. Note the outer diameter D 3 of the flange  108   a  is less than the diameter D 4 of the handle storage tube Th so that the handle can be easily retracted to a storage position. 
   The handle pivot attachment rod  108  has a radial orientation pin  120  which registers with a notch  122  in the pivot trunnion  112  to align the holes and through port in the pivot trunnion to allow insertion of the locking pin  120  to lock the handle in the outer limit position. 
   The cart may be provided with detachable walls which can be mounted to the periphery of the top cover C in the manner shown in  FIGS. 12 and 13 . In this instance the side panels  130  have inwardly directed flanges  132  at opposite ends and at least one key hole slot. The front and rear panels mount buttons  138  adjacent the outer side edges which are oriented to engage in the key hole slot  134  in the side panel  130  and the key hole slot S in the front and rear walls  16   f  and  16   r  of the side walls  14  of the top support cover Cs in the manner shown in  FIGS. 13 and 14 . 
   Even though a particular embodiment of the invention has been illustrated and described herein, it is not intended to limit the invention and changes and modifications may be made therein wither the scope of the attached claims. For example, the braces may be secured to the top cover by other means such as welding. Further in the embodiment illustrated the wheel assembly is independently actuatable between extended and retracted limit positions and can readily be linked together to provide simultaneous movement between limit positions. Even though the specific means for securing the handle in the extended and stored positions is an important feature of the present invention, other locking arrangements are possible.