Abstract:
A car seat for several children and to sit on top of a regular car seat has leg assemblies arranged to absorb energy and reduce pitching in the event of a car crash.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This national stage application claims the benefit under 35 U.S.C. §371 of International Application No. PCT/GB2004/002834 filed on Jul. 1, 2004, entitled CHILDRENS SAFETY SEAT, which in turn takes its priority from British Application No. 0315495.2 filed on Jul. 2, 2003, and all of whose entire disclosures are incorporated by reference herein. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a children&#39;s safety seat and is particularly concerned to provide a seat that can conveniently be fitted into, and removed from, a motor vehicle as required, to enable more than one child to be safely accommodated. 
   2. Description of Related Art 
   Child safety seats are well known and usually comprise an individual child&#39;s seat which can be removably connected into a suitably anchored restraining harness on the back seat, or, in some instances, the front seat, of a motor car. Such seats are useful for children weighing up to about 35 kg. 
   Problems arise when it is necessary to cater for more than one child. Although it is quite possible to arrange for two separate safety seats to be releasably anchored on the rear seat of a car, it is difficult to cater for three children and virtually impossible for four. Moreover, the fitting of anchorage for a multiplicity of safety seats is time-consuming and expensive and the purchase and physical handling of a number of seats expensive and inconvenient. 
   FR-A-2 559 043 discloses a children&#39;s safety seat to be securely and releasably attached to points in a motor vehicle when positioned on an existing seat of the vehicle; the safety seat having a back portion and a base portion which are subdivided to provide two individual seats, whereby the seat has integral means which enable it to be anchored in position. 
   EP-A-0574848 discloses a rearward-facing seat for a small child mounted on an ordinary passenger seat and held in place by a combination of a frame and straps. By this means the safety seat can be positioned on a seat in a vehicle to face backwards with the head of the child comfortably above its feet in a semi-reclining position. 
   BRIEF SUMMARY OF THE INVENTION 
   It is an object of the invention to provide a safety seat that is suitable for more than one child and that is more convenient than current arrangements to deal with more than one child and can absorb impact energy better than other known seats. 
   My European patent 0844938 (which is not a prior publication) discloses a child&#39;s safety seat comprising a plurality of seats for fitting onto the existing back seat of a motor car. One of the problems found with this design of seat is that when there are, for example, four occupants in four seats the total weight of the occupants imposes high loads on the strap restraints that hold the seat into place in the car. In the event of severe braking of the car or in a crash or impact, the seat tends to tilt forwards with the front edge of base portion, or seat, dipping unacceptably downwards. 
   A further object of the present invention is to provide a seat of the type described and claimed in my European patent 0844938 with additional energy absorbing leg assemblies that locate on rigid structure of the car to stabilise the seat and reduce or eliminate unacceptable pitching forward of the seat. 
   According to one aspect of the present invention, there is provided a safety seat comprising, a seat body including a base portion for being positioned on an existing seat of a vehicle and a back portion extending up from the base portion, divider means connected to the seat body for sub-dividing the seat body to provide a plurality of individual seats for accommodating two or more children side-by-side, releasable anchoring means for connecting the seat body to anchorage points in the vehicle for securing the seat body therein; characterised by support leg assemblies for engaging a body of the vehicle below the base portion and for supporting and providing additional rigidity to the seat body, the support legs being connected to the base portion for vertical and horizontal movement with respect to the base portion, the leg assemblies incorporating energy absorbing means adapted to absorb energy in the event of the vehicle being involved in an accident. 
   In a second aspect the invention provides a safety seat comprising a seat body including a base portion for being positioned on an existing seat of a vehicle and a back portion extending up from the base portion, divider means connected to the seat body for sub-dividing the seat body to provide a plurality of individual seats for accommodating two or more children side-by-side, releasable anchoring means for connecting the seat body to anchorage points in the vehicle for securing the seat body therein; support leg assemblies for engaging a body of the vehicle below the base portion and for supporting and providing additional rigidity to the seat body, the support leg assemblies being connected to the base portion for vertical and horizontal movement with respect to the base portion, the leg assemblies comprising an upper generally horizontal portion and a vertical portion, wherein the horizontal portion is adapted to absorb energy in the event of the vehicle being involved in an accident. 
   In a third aspect there is provided a children&#39;s safety seat, wherein the seat body has elongate sockets extending in a forwards direction when the seat is located in the vehicle, and the sockets are positioned, dimensioned and arranged to accommodate part of the legs of the preceding paragraph. 
   The legs are preferably adjustable for width and height so as to be applicable to a variety of vehicles and they may bear down, for example, on the inner sills of the vehicle or on the floor pan of the vehicle to provide additional rigidity and support to the seat. 
   The leg assemblies can take a variety of forms. Preferably the leg assemblies comprise an upper horizontal portion (like a thigh); a knee portion; and vertical leg portion. In one embodiment, an energy absorber is present in the leg, preferably the vertical portion; and/or the horizontal portion may move telescopically in a socket below the seat; and/or the knee portion may bend and/or the horizontal portion may be arranged to bend upwardly. 
   In a particularly preferred embodiment, the seat is designed to extend for substantially the full width of a vehicle&#39;s existing back seat on which it is to be positioned. Thus, it may be of a length to fill completely the width of the rear seat of a motor car. It may be specifically designed to fit the full width of a particular make and model of car. 
   Such a full width children&#39;s seat may conveniently be sub-divided to provide four individual child&#39;s seats in the one integral seat. Alternately, it may be sub-divided to form three slightly larger seats for children or two or three children&#39;s seats and one adult seat. 
   Preferably the seat is integrally-moulded of plastics material to form a sufficiently strong and rigid integral back and base portion with integrally-formed sub-divisions in the form of protrusions on the back and/or base portions to define the individual seats. 
   The anchorage means for anchoring the seat to the vehicle may be suitably positioned holes or slots moulded into the seat to receive anchorage straps for attachment to secure anchorages on the vehicle in a conventional manner. 
   Alternatively the seat may be a welded metal frame having the back and base portions and welded subdividers. Suitable anchorage holes and slots may then be drilled in the desired locations. 
   The seat may carry suitable padding and decorative covering material together with individual harnesses for each child&#39;s seat portion, as is conventional. 
   Although it is preferred to fit the seat onto the existing back seat of a vehicle, it is not necessary that the seat be designed to fit onto the back seat of a car. It may, if desired, be designed to fit onto the front passenger seat, in which case it will normally be of a length to provide seats for two children, i.e. it will have one set of sub-dividers. 
   It is a requirement of law in certain countries that very young children must sit in a rearward-facing seat. For example, in the United Kingdom, children up to 9 kg. in weight (approximately up to 10 months) must be seated in a rearward facing seat as their necks are insufficiently strong to support their heads in the event of a frontal collision of the vehicle in which they are travelling. In Sweden, children up to 4 years of age must be seated in rear-facing seats for similar reasons. 
   The shell may be an integral moulding of suitable plastics material and the stand and projections may be part of the integral moulding. 
   Alternatively, as indicated above the shell may be of welded metal construction. 

   
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
     Embodiments of the invention will now be described by way of example only with reference to the accompanying diagrammatic drawings in which: 
       FIG. 1  is a perspective view of one form of chassis for a children&#39;s seat of the type described in EP 0844938 modified to incorporate the present invention; 
       FIG. 2  shows the chassis of  FIG. 1  upholstered and fitted with safety harness; 
       FIG. 3  is a perspective view of a seat of the invention being presented to a seat chassis similar to that of  FIG. 1  and incorporating the present invention; 
       FIG. 4  is a similar view to  FIG. 3  showing the seat mounted in the chassis; 
       FIGS. 5 and 6  are perspective views of modifications that may be applied to the seat of the invention; 
       FIGS. 7 and 8  are views of seats similar to that of  FIGS. 1 and 2  but having an adjustable leg in accordance with the present invention, and 
       FIGS. 9A and 9B  show diagrammatically what happens to another leg assembly of the invention in the event of a crash. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to the  FIGS. 1 and 2  a children&#39;s seat body in accordance with the present invention comprises a chassis  10 , as shown in  FIG. 1 , which is upholstered as shown in  FIG. 2 . The chassis  10  has an integral back portion  11  and a base portion  12 . The seat has three sets of dividers  13  and end fittings  14  at each end to define four separate child&#39;s seats  15 , 16 , 17  and  18 . Slots  19  along the dividing line between back  11  and base  12 , and slots  19  in the back  11  and  21  in the base  12 , provide means to receive anchorage straps  22  for anchoring the chassis  10  to the vehicle&#39;s safety seat anchorage points. The slots  20  and  21  also provide means to receive child&#39;s harness straps  23  while providing means for adjustment as required. 
   The seat body  10  is designed to sit on top of the vehicle&#39;s existing seat cushions (not shown) and not used in place of the existing seat. The base portion  11  of the chassis  10  sits on top of the existing seat cushions of the vehicle&#39;s existing seat whereas the back portion  12  of the chassis  10  lies adjacent the backrest part of the vehicle&#39;s existing seat. 
   In accordance with the present invention, the seat chassis  10  is provided with rectangular-shaped (but could be of any desired cross-sectional shape) elongate sockets  24  that are positioned, shaped and arranged to receive and retain adjustable legs  25 . The legs  25  are provided at each front corner of the chassis  10  but this is not necessary in all cases. The legs  25  are of a shape complementary to that of the sockets  24 . In the drawing they are shown as of rectangular cross-sectional shape. The legs  25  are made of a hollow tube that is bent in a right angle to form a horizontal portion  25   a  and a downward projecting portion  25   b . At the free end of the downward portion  25   b  of the leg  25 , a captive screw-threaded nut  25   c  is located inside the tube  25   b . A screw-threaded foot  26  is screwed into the captive nut  25   c . If desired, a lock nut (not shown) may be screwed onto the screw thread  26   a  of the foot  26 . 
   The leg assembly is designed to absorb energy either by foot built as an energy absorbing structure (see below), as the lower leg sliding telescopically inside the upper leg or the horizontal portion of the leg deforming in a controlled manner. As shown in  FIG. 1 , the foot  26  is provided with an energy absorbing structure  28  that, in the event of an accident, absorbs energy. The energy absorbing structure  28  is preferably made from a material manufactured by Cellbond Composites Ltd called Hyload or Pressload. This material is designed to crumple in a controlled manner when subjected to compressive impact loads in excess of a predetermined threshold value. The energy absorbing structure  28  is preferably an integral part of each leg. That is to say the foot  26  of each leg  25  is bonded or secured to the pad  28 . If desired the pad  28  need not be bonded or secured to each leg but in this case the pad  28  needs to have means, such as a recess or socket in which the foot  26  locates so that the pad  28  does not get dislodged from under the respective foot  26 . 
   If desired, the captive nut  25   c  may be secured to an energy absorbing material (not shown) located inside the lower portion  25   b  of the leg  25 . This energy absorbing material is the same as that shown as  28  in  FIG. 1  but would be designed to crumple in a controlled manner when the foot  26  is subjected to an impact load above a predetermined value that shears the fixing of the foot  26  to lower portion  25   b  and compresses the energy absorbing material inside the tube  25   b  of the leg  25 . 
   The horizontal portion  25   a  of the legs is designed to deform in the event of a crash that would subject the legs  25  to impact loads. 
   Preferably the legs  25  are padded with externally mounted padding (not shown) to minimise injury to the occupants in the seats. 
   It will be appreciated that the legs  25  are insertable into the sockets  24  by varying amounts to accommodate different car rear seat depths, and are adjustable to accommodate different heights of car seats by screwing the foot  26  up and down relative to the legs  25 . The horizontal portions  25   a  of the legs  25  may be provided with ratchet surfaces (not shown) that co-operate with spring loaded pawls (not shown) that project into the bore of the sockets  24  to engage the ratchet surfaces so that the legs  25  may be locked in place in the sockets  24  to accommodate different depths of car seats. 
   In the event of a crash, a leg  25  will tend to bend at its thigh portion, so lifting the foot off the floor of the vehicle. With such a structure, the energy absorbing foot can be dispensed with. 
   If desired, an energy absorbing material (similar to the material  28 ), may be located inside the sockets  24  so that if the legs  25  are subjected to an impact load in excess of a threshold value in the event of an accident, the leg  25  slides in the sockets  24  to compress the energy absorbing material (and thereby expend energy) in a controlled manner. 
   As indicated above and as shown in  FIG. 2 , the seat  10  will normally be upholstered with cloth covered padding to provide comfort and a pleasing appearance and will be fitted with releasable safety straps or harness  23  to hold each child in position. 
   In  FIG. 3  is shown a detachable baby&#39;s safety seat  30  for use with a seat chassis ( 10 ) that is similar to the seat chassis shown in  FIG. 1 . The safety seat  30  has a body shell  33  of generally rectangular plan form. At one shorter edge  34  it has a projecting locating tongue  35 . Underneath it has a stand  36  containing a slot  37  and two projecting feet  38 . It is upholstered internally by conventional means and has a safety harness  39  and straps  40  by which it can be carried when not in use in a vehicle. 
   Seat chassis  10  has a back portion  11  and a number of seat portions  11   a  similar to that of the chassis  10  of  FIG. 1 . Again the chassis  10  is provided with two sockets  24  (only one is shown but, as in  FIG. 1 , there are two sockets  24 ) to receive legs  25  which are of the same design as shown in  FIG. 1 . The back  11  and seat portions  12   a  contain a different array slots  19 ,  20 , by which the seat chassis  30  may be anchored to the vehicle&#39;s anchor points, using straps (not shown). Additionally, back portion  11  contains a slot  34  to receive the locating tongue  35  of seat  30  and the seat portion  11   a  contains slots  41  to receive feet  38  of stand  36  of seat  30 . The seat  30  may thereby be located on and locked to the seat chassis  10  (see  FIG. 4 ). 
   As an additional locking means, seat portion  11   a  of seat  10  is provided with a clip  42  that locates in slot  37  of stand  36 . A baby can therefore be securely carried in seat  30  while facing rearward relative to the vehicle in which the seat is used. The seat  30  is provided with carrying handles  40  so that the seat may be lifted into or out of the car and has straps  39  forming a harness to hold a baby or infant in the seat  30 . 
   It will be seen that the seat  30  when installed faces rearwards with the front edge of seat  30  slightly higher than the rear edge of the seat  30 . 
   Seat  10  has been shown non-upholstered in  FIG. 3  or  4  for convenience, but it will be appreciated that all the seat portions on all but the one (or those) that is to receive the seat  30  may be upholstered in a similar way to that shown in  FIG. 2 . 
   In  FIGS. 5 and 6  are shown two modifications to the seat body  10 . Here again the chassis  10  is provided with sockets  24  to receive legs  25  that are of the same design as shown in  FIG. 1 . In  FIG. 5 , chassis  10  has a series of slots  61  in its upper edge  62  to receive head restraints  63  or  64  which have legs  65  to fit into slots  61 . In  FIG. 6  the seat  10  is provided with a divider screen  71  which fits into suitable slots  55  (see  FIG. 1  or  FIG. 3 ) in the chassis  11  through slots in the upholstery located between individual seats. The screens  71  may be useful in “curtaining off” one seat from another, which may be beneficial when carrying two or more small children. 
   In  FIG. 7  a seat  10  of the invention is identical to the seat  10  of  FIG. 1  except that it has a hollow socket  24  extending in a direction transverse to the vehicle along its front edge. Here again the chassis  10  is upholstered as shown in  FIG. 8 . 
   The socket  24  is open at each end to receive a side extension  25   a  of a leg  25  that is of a similar design to that shown in  FIG. 1 . The lower end of the vertical portion  25   b  of each leg  25  has a screw-in foot  26  that is screwed into a captive nut  25   a  inside the leg  25 . Thus the legs  25  can be adjusted horizontally (sideways when fitted on to a car seat) by virtue of the degree of penetration of extension into hollow socket  24 , thereby adjusting the width between the pair of legs  25 , and vertically by virtue of the amount foot  26  is screwed into leg portion  25   b . The legs  25  are provided with an optional energy absorbing pad  28  identical to the pad  28  shown and described in connection with  FIG. 1 . Similarly, energy absorbing material similar to  28  may be incorporated inside the sockets  24  for the same purpose as described above. If desired, energy absorbing material  28  may be provided inside the downward projecting portion of each leg  25  as described in connection with  FIG. 1 . 
   In use, a seat body of  FIGS. 2 to 8 , comprising an upholstered chassis  10  is located on top of the seat cushions of the existing back seat of a vehicle such as a car. The seat  10  is secured to the vehicle&#39;s safety seat anchor points (not shown) by way of safety straps  21  (shown schematically in  FIG. 1 ). The straps  21  will vary in length and direction depending upon the make of vehicle to which the seat  10  is fitted. If seats  30  are to be used, one or more are fitted to the chassis  20  as described above. 
   A harness comprising straps  39  is fitted into the appropriate slots in the chassis and lengthened or shortened to suit the size of each child. A child is then strapped into each seat using the harnesses  39 . 
   Because the width of a seat  10  of the invention can be tailored to the full width of the rear seat of the car to which it is to be fitted, it can be anchored very securely in position, even if wheel-arches protrude into the car seat edges, so that there is little or no tendency for the safety seat to slide about. 
   As explained, in the event of a crash, energy is absorbed by the telescoping of one leg tube portion in the other and/or the lower leg deforming and/or crushing the energy absorbing material with the foot. 
   In the embodiment of  FIG. 9 , the leg  40  consists of an upper horizontal or thigh portion  41  and a lower vertical portion  42  which is at right angles to the upper portion. The upper portion consists of a square section tube  43  having at the end remote from the seat an inner reinforcing bar  44 . The horizontal portion extends into the slot  24  adjacent the seat by a distance of about 350 mm, so that the inner end of the bar  44  is adjacent the forward end of the seat. The lower portion consists of a straight portion  45  ending in a small foot  46 . As shown in  FIG. 9 , the leg is free of a shock absorbing pad which enables the foot print to be small and the component cost is reduced. In the event of a crash, the horizontal leg  41  deforms about the forward end of the seat and as shown in  FIG. 9B , tends to bend around the point at which the thigh portion extends forward of the slot  24  and the leg  42  may be lifted up off the floor once the shock has been absorbed.