Abstract:
An apparatus for transporting a child safety seat includes a wheeled assembly a clamping bracket for applying a clamping force to the back of the child safety seat and positioning members to ensure that the apparatus is properly positioned relative thereto. The apparatus with attached child safety seat may be wheeled on the ground by a person using one hand. The apparatus is fully detachable from the child safety seat.

Description:
FIELD OF THE INVENTION 
   The present invention relates to transporting a child safety seat such as an infant car seat, child car seat, or a child booster seat. In particular, the invention relates to a two-wheeled dolly for transporting a child safety seat by wheeling it on the ground. 
   BACKGROUND OF THE INVENTION 
   The use of child safety seats for the safe restraint of infants and children in vehicles is well known. For the safety and comfort of an infant or child, and also to comply with applicable laws requiring the use of child safety seats for children of specified ages, child safety seats now are commonly removed from the family vehicle and taken along on travels. For example, a child&#39;s child safety seat may be used for the child in a rental car on the family vacation. In addition, child safety seats commonly may be used in other modes of transportation, such as airplanes, buses, boats, or trains, to provide a safer and more comfortable seat for young children. 
   Such use of child safety seats away from the family vehicle thus requires the transport of the child safety seats through airport terminals, bus stations, train stations, boat terminals, and the like. The typical infant or child safety seat is quite bulky, of an awkward shape, and may weigh between ten and twenty pounds. Thus the physical size, structure, and weight of the child safety seat make it difficult to carry and for most persons, require the use of both hands. This is particularly necessary if the child safety seat is carried for a substantial distance. 
   Various devices have been developed to assist with the transport of child safety seats, including a wide variety of bags, totes, and cases. Typically these travel bags comprise a zippered sack, with a handle and/or shoulder strap. The child safety seat may be placed in the sack and then carried from the family vehicle to baggage check, or onto the airplane, bus, etc. 
   Alternatively, some models of child safety seats are provided with wheels and a handle, essentially converting the child safety seat into a stroller so that it can be wheeled through an airport or other area. In addition, stroller-type attachments are made for child safety seats, again converting the child safety seat to a stroller-like apparatus that can be wheeled to its destination. Typically, a child young enough to require the use of a child safety seat is also too young to walk any considerable distance through an airport terminal, train station, etc. This generally requires that the child also be carried, typically in a stroller, a backpack or front carrier, or simply in the guardian&#39;s arms. In addition, travel with young children generally entails transporting various other equipment, such as diaper bags. As a result, persons transporting young children while traveling must potentially negotiate a number of large, awkward items, in addition to the child. 
   A prior solution in which the wheels and handle are separately formed and attached to a child safety seat is disclosed in U.S. Pat. No. 6,267,821. Solutions is which the wheels and handle are formed in one unit separable from the child safety seat are disclosed in U.S. Patent Publication No. 2003/0192925 A1, and U.S. Pat. Nos. 6,729,620 and 6,783,135. The contents of these published applications and issued patents are incorporated by reference. 
   SUMMARY OF THE INVENTION 
   In one aspect, the present invention is directed to a child safety seat dolly assembly having a dolly frame, a pair of horizontally spaced apart positioning members attached to the dolly frame, and a clamping bracket, the assembly being adjustable between a first, disassembled state in which the clamping bracket is separated from the dolly frame, and a second, assembled state in which the clamping bracket is attached to the dolly frame. The dolly frame has a first side facing in a first direction, a pair of wheels rotatably mounted on the dolly frame at a lower portion thereof, and a handle member. The horizontally spaced apart positioning members project are located on a lower portion of the dolly frame and project in the first direction. The clamping member has a front face, a back face, and first and second end faces. The clamping member also has at least one leg projecting from the back face in a direction transverse to the body member, and first and second clamping surfaces located on the back face, the first clamping surface located between said at least one leg and the first end face and the second clamping surface located between said at least one leg and the second end face. 
   Preferably, the clamping member has two legs. In such case, the clamping bracket is secured to the dolly frame via a pair of bolts that pass through the first and second legs and through a pair of spaced apart through holes formed on the body frame. A pair of thumb screws may be employed to secure the bolts to the dolly frame. In addition, in the assembled state with the dolly assembly in an upright position, the clamping bracket&#39;s clamping member extends in a horizontal direction. Furthermore, in the assembled state with the dolly assembly in an upright position, the clamping bracket&#39;s clamping member extends past left and right side edges of the dolly frame, in either a front or rear view of the dolly. 
   In another aspect, the present invention is directed to a child safety seat dolly including a dolly frame, a pair of horizontally spaced apart positioning members attached to a lower portion of the dolly frame, and a clamping bracket removably secured to the dolly frame, the positioning members and the clamping bracket projecting in a common direction relative to the body frame. The dolly frame has a first side facing in a first direction, a pair of wheels rotatably mounted on the dolly frame at a lower portion thereof, and a handle member. The clamping bracket includes a clamping member having a front face, a back face, and first and second end faces, first and second legs projecting from the back face in a direction transverse to the body member; first and second clamping surfaces located on the back face, the first clamping surface located between the first leg and the first end face, and the second clamping surface located between the second leg and the second end face. The clamping bracket&#39;s first and second legs are spaced apart in the horizontal direction and the clamping bracket&#39;s clamping member is horizontally oriented in a front view of the dolly when the dolly is in an upright position. 
   In yet another aspect, the present invention is directed to a child safety seat dolly in combination with a child safety seat. The dolly comprises a dolly frame, a pair of horizontally spaced apart positioning members, and a clamping bracket removably secured to the dolly frame and comprising a clamping member have a pair of spaced apart clamping surfaces facing in a direction of the dolly frame, the positioning members and the clamping bracket projecting in a common direction relative to the body frame. The child safety seat comprises a pair of spaced apart apertures in which said positioning members are received, and a pair of spaced apart abutment surfaces against which the pair of spaced apart clamping surfaces clampingly abut, thereby securing the child safety seat to the child safety seat dolly. 
   When such a combination is at rest on a flat surface, a base portion of child safety seat and a pair of wheels attached to the dolly frame both contact the flat surface. 
   In still another aspect, the present invention is directed to a method of securing a child safety seat dolly to a child safety seat. The method includes the steps of positioning a clamping bracket having first and second clamping surfaces against a pair of spaced apart abutment surfaces formed on a rear portion of the child safety seat, inserting a pair of spaced apart positioning members provided on the dolly into a pair of apertures formed on a rear portion of the child safety seat, receiving ends of bolts attached to the clamping bracket into holes formed in the dolly; and placing and then turning thumb screws on ends of the bolts, after the bolts have passed through said dolly. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will now be described with respect to the following figures in which: 
       FIG. 1  is a partially exploded perspective view of a dolly in accordance with the present invention; 
       FIG. 2  is a front view of an assembled dolly of  FIG. 1  in an upright position with the handle in the deployed position; 
       FIG. 3  is a rear view of an assembled dolly of  FIG. 1  in an upright position with the handle in the retracted position; 
       FIG. 4  shows a perspective view of the clamping bracket; 
       FIG. 5  illustrates the back portion of a child safety seat for which the dolly of the present invention is suitable; 
       FIG. 6  shows a dolly of the present invention about to be mated with a child safety seat; and 
       FIG. 7  shows a dolly of the present invention mated with a child safety seat. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows a partially exploded view of a dolly  100  in accordance with the present invention. The dolly  100  has two wheels  102   a ,  102   b  attached to a lower portion  122   a  of a dolly frame  104 . In a preferred embodiment, the dolly frame comprises a substantially flat body member  104 . The body member  104  has a front side  104   a  defining a first plane, and a back side  104   b . The body member  104  has a lower portion  122   a  with a first width, a tapered portion  122   b , and an upper portion  122   c  having a second width which is smaller than first width. The tapered portion is connected on a lower side to the lower portion and on an upper side to an upper portion  122   c.    
   Attached to the body member  104  is a telescoping handle member  106  provided with parallel legs  106   a ,  106   b  and a handle release  107  in a top surface thereof. The handle member has a pair of legs  108   a ,  108   b  that are fixedly mounted in sleeves  110   a ,  110   b . The sleeves  110   a ,  110   b  are provided proximate an upper edge of the upper portion  122   c  of the body member  104 . 
   Critical to the present invention, the front side  104   a  of the body member  104  is provided with a plurality of mating structures  116   a ,  116   b  and  118 , all of which protrude from the front face  104   a  of the dolly&#39;s body member  104 . 
   Spaced apart lower mating structures  116   a ,  116   b  are provided on the lower portion  122   a  of the body member  104 . The lower mating structures preferably have unitary construction with the body member  104  and thus the body member and the lower mating structures may comprise a single continuous piece of common molded material, such as a hard plastic. In a preferred embodiment, the lower mating structures  116   a ,  116   b  serve as positioning members. Centers of the positioning members  116   a ,  116   b  are separated by a distance d 1 . The positioning members  116   a ,  116   b  are at the same vertical height from a surface on which the dolly  100  is held in an upright position. Preferably, they are placed along a lower edge  126  of the body member  104 . The positioning members  116   a ,  116   b  are configured and dimensioned to locate the dolly relative the back side of a child safety seat, as discussed further below. 
   In a preferred embodiment, the positioning members  116   a ,  116   b  have a prismoidal shape with a height h 1 , a width w 1  and a depth taken in a direction normal to the front face  104   a  of the body member  104 . The values of these three parameters may vary depending on the dimensions of structures on the back surface of a child safety seat to which the positioning members are mated. In particular, at least the height h 1  and width w 1  preferably are such that there remains little clearance between the outer surfaces of the positioning members and the structures to which they are mated. 
   The upper mating structure  118  is spaced apart in the vertical direction from the lower mating structures  116   a ,  116   b . As seen in the figures, in a preferred embodiment, the upper mating structure  118  is in the form of a pi-shaped clamping bracket (Greek letter ‘π’)  100 . The clamping bracket  118  comprises a horizontally extending clamping member  130  of length d 3  and having a front face  130   a  and an oppositely facing back face  130   b . First and second legs  132   a ,  132   b  extending at right angles to the clamping member  130  are provided on the back face  130   b . The legs serve to hold the horizontally extending clamping member  130  away from the body member  104 . 
   The back face  130   b  has first and second lateral surfaces  134   a ,  134   b , respectively. The lateral surfaces are located between each leg  132   a ,  132   b  and its associated end face  136   a ,  136   b  respectively. At least a portion of these lateral surfaces  134   a ,  134   b  serve as clamping surfaces. Thus, in the assembled dolly, the lateral surfaces  134   a ,  134   b  face in the direction of the body member  104  and the clamping force is directed towards the body member  104 . 
   In a preferred embodiment, the legs  132   a ,  132   b  of the clamping bracket  118  are attached to body member  104  via bolts  138   a ,  138   b . Bolts  138   a ,  138   b  are inserted through the front face  130   a  of the clamping member  130 , pass through the legs  132   a ,  132   b  and through holes  140   a ,  140   b  formed in the body member  104 . The terminal ends of the bolts  138   a ,  138   b  that protrude on the back face  104   b  of the body member  104  are secured by placing and then turning manually manipulable thumb screws  142   a ,  142   b , respectively. 
   In  FIG. 1 , the dolly may be considered to be in a disassembled state since the clamping bracket  118  is not attached to the body member  104 . In  FIGS. 2 and 3 , on the other hand, the dolly  100  is in the assembled state with the clamping bracket secured to the body member  104 . As seen in  FIGS. 2 and 3 , in both a front view and a rear view of the dolly  100  in the assembled state, the ends of the clamping member  130  extend laterally beyond the left and right side edges  127   a ,  127   b , respectively, of the body member  104 . And, as seen in  FIG. 3 , at least a portion of the lateral clamping surfaces  134   a ,  134   b , are visible in a rear view of the dolly  100 . 
     FIG. 4  shows the back side  402  of a child safety seat&#39;s seating portion  400 . The seating portion  400  is pivotally mounted on an associated base portion (not shown in  FIG. 4 ) which permits tilting of the seating portion  400 . The back side  402  includes a pair of spaced apart, vertically extending side supports  404   a ,  404   b . The side supports  404   a ,  404   b  extend in a rearward direction from the seatback  406 . Preferably, the side supports and seatback are all molded together. Side supports  404   a ,  4040   b  each have a side aperture  410   a ,  401   b  extending in a direction transverse to the side supports. 
   Since the side supports are very similar, only side support  404   a  is described, it being understood that side supports  404   b  is a mirror image of support rail  404   a . Side support  404   a  comprises an inner wall  408   a  and an outer wall  408   b . The inner wall  408   a  and outer wall  408   b  are substantially parallel to each other at the base  408 , but merge with one another near the top  409 . 
   At its rearwardmost portion, the side support  404   a  is provided with a plurality of horizontally extending support fins  502   a ,  502   b ,  502   c , etc., which connect the inner wall  408   a  and the outer wall  408   b . The support fins lend structural rigidity to the side support  404   a  while minimizing weight. The inner and outer walls  408   a ,  408   b  and adjacent support fins  502   a ,  502   b  define therebetween a locating aperture  504   a  that is located at the rear of the side support  404   a  and is open in the rearward direction of the seating portion  400 . It is understood that the other side support  404   b  also has a similar locating aperture  504   b . The back of the child safety seat disclosed in U.S. Pat. No. 5,611,596, whose contents are incorporated by reference, discloses similar support fins. 
   The centers of the side supports  404   a ,  404   b  are separated by a horizontal distance d 1 , which corresponds to the horizontal distance between centers of the positioning members  116   a ,  116   b . The vertical spacing h 2  between adjacent support fins  502   a  and  502   b  is just slightly greater than a height dimension h 1  of positioning members  116   a ,  116   b . Meanwhile the horizontal extent w 2  of one or more of the support fins  502   a ,  502   b ,  502   c , is just slightly greater than a width dimension w 1  of positioning members  116   a ,  116   b . Finally, the positioning members  116   a ,  116   b  on an upright dolly and the locating apertures  504   a ,  504   b  (by virtue of the associated base portion) are at a substantially similar height above a common ground surface on which both are placed. Thus, the positioning members  116   a ,  116   b  are configured and dimensioned, and also located relative to one another on the dolly  100 , to be received in locating apertures  504   a ,  504   b.    
   The inner walls of the side supports  404   a ,  404   b  are spaced apart by a distance d 2  at a point where the side apertures  410   a ,  401   b  are formed. This distance d 2  is less than the length d 3  of the clamping bracket&#39;s clamping member  130 . 
     FIG. 6  shows a dolly about to be mated to a child safety seat having a child safety seat base  602  and a seating portion. The child safety seat shown in  FIG. 6  and  FIG. 7  preferably is similar to one or more of the seats shown in aforementioned the U.S. Pat. No. 5,611,596. 
   To employ the dolly  100 , one first places the clamping bracket  118  such that it is supported near its opposite ends  136   a ,  136   b  within the side apertures  410   a ,  410   b , respectively. The clamping bracket  118  may be wedged into position, depending on the spacing between opposing rear and front faces  152   a ,  152   b , respectively, of the side apertures  410   a ,  410   b , and also depending on the thickness of the clamping member  130  at the clamping surfaces  134   a ,  134   b . Alternatively, the clamping bracket may temporarily be supported by structures provided on the opposing faces  152   a ,  152   b  of the side apertures. If necessary, the clamping bracket  118  is rotated such that the legs  132   a ,  132   b  face in the rearward direction with the bolts  138   a ,  138   b  protruding through the legs. 
   With the clamping bracket in place, the remainder of the dolly is then brought towards the bolts  138   a ,  138   b  until the bolts pass through the through holes  140   a ,  140   b  formed in the body member  104 . At this point, the clamping surfaces  134   a ,  134   b  press against the forward faces  152   a  of the side apertures  410   a ,  410   b , which serve as abutment surfaces  152   a . And at about the same time the bolts  138   a ,  138   b  pass through the through holes, the positioning members  116   a ,  116   b  are aligned with, and are then inserted into, the locating apertures  504   a ,  504   b . Once the bolts protrude through the back side  104   b  of the body member  104  and the positioning members are received into the locating apertures, the thumb screws  142   a ,  142   b  are then turned and hand-tightened to secure the dolly  100  to the seat portion  400  with the clamping surfaces  134   a ,  134   b  applying a clamping force against the abutment surfaces  152   a  of the side apertures  410   a ,  410   b.    
   The foregoing process in the assembly of  FIG. 7  where the dolly  100  is in combination with a child safety seat with the clamping bracket  118  forcing a rear portion of the car seat against the front side  104   a  of the body  104  whilst the positioning members are positioned in the locating apertures. Thus, the child safety seat comprises a pair of spaced apart apertures  504   a ,  504   b  in which said positioning members  116   a ,  116   b , respectively, are received, and a pair of spaced apart abutment surfaces  152  against which the pair of spaced apart clamping surfaces  134   a ,  134   b  clampingly abut, thereby securing the child safety seat to the child safety seat dolly. 
   One feature of a dolly in accordance with the present invention is that it does not require the child safety seat to be modified. This obviates the need to permanently change any existing components or attach any new components, either of which may violate regulations an specifications governing such seats. Thus, a dolly in accordance with the present invention may be used in conjunction with prior art child safety seats having the necessary structures to mate with the clamping bracket and the location members. 
   Another feature of a dolly in accordance with the present invention is that, as seen in the assembled position of  FIG. 7 , both the wheels and the car seat base  602  can simultaneously touch the ground when the combination is at rest. This means that only a minimal degree of tilting is required to provide sufficient clearance for transporting the child safety seat using the dolly. 
   In the foregoing description, the clamping force was applied in the rearward direction with the clamping bracket&#39;s clamping surfaces pressing against the front faces of the side apertures. It is noted that the clamping surfaces may press against other formations provided on the back side of a child safety seat, as well. Furthermore, the positioning members may be mated to location apertures situated in locations other than those shown in the preferred embodiment. Thus, the dolly of the present invention may be marketed with the clamping bracket and the positioning members in different configurations that are matched to specific models of child safety seats. 
   Although the present invention has been described to a certain degree of particularity, it should be understood that various alterations and modifications could be made without departing from the scope of the invention as hereinafter claimed.