IMPROVEMENTS IN CAR SEATS FOR CHILDREN

Abstract: In order to adjust a harness relative to the back-rest of a child's car safety seat (1), the back-rest is provided with a pair of generally upwardly extending slots (221) through which shoulder belts of the harness may extend. The position at which each shoulder belt passes through a slot is determined by guides (222) capable of being made fast with the back-rest. A pressure plate (229) has fingers (230) which cooperate with a finger (242) of a cowl (240). The conventional seat belt of a vehicle may be threaded between the fingers to displace a cam member (232) over which the belts pass, so as to increase the tension in the belts.

Description: IMPROVEMENTS IN CAR SEATS FOR CHILDREN This invention relates to a safety seat of the type which may be used to retain a child safely during car travel. The invention is particularly, although not exclusively, concerned with a safety seat of the type which rests on a passenger seat of the vehicle during car travel, but may be removed from the vehicle and used to carry the child using a handle pivoted to the body of the seat. When in the vehicle, the seat may be arranged to face to the rear and be held in place by a car seat belt. Known car safety seats intended for children suffer from disadvantages, particularly in connection with making adjustments to take account of increases in the size of the child using the seat. In one known type of child's car safety seat, the back- rest of the seat is provided at each side with three slots arranged one above another. A child retention harness includes a pair of shoulder belts , each of which is passed through a slot at a height appropriate to the size of the child, initially through the lowest slot. The shoulder belts are connected by a releasable fastener to a lap or crotch belt which is taken out through an opening in the bottom of the seat and may be pulled through a clamp to tension the harness. As the child grows, the shoulder belts must be extracted from the lowest slots and threaded through slots at a higher level. This adjustment should not be made until the child's shoulders have reached the level of the next pair of slots, but in practice adjustment may be carried out prematurely or be delayed. This may increase the risk of injury to the child during a crash. It is clearly desirable for the system for adjusting the harness to be simplified, made easier to use, and ensure optimum positioning of the belts relative to the child's shoulders . It is also desirable in a seat of this type for the tension in the harness to be relaxed slightly for comfort when the seat is removed from the car to carry the child, as it is then unnecessary to restrain the child quite so firmly as during travel. Moreover, it is also desirable for the contour of the seat to be adjustable to allow very small babies to lie relatively flat when being transported, instead of in a sitting position. Various aspects of the present invention meet these desiderata in particularly effective ways. According to a first aspect of the invention there is provided a car safety seat for a child, the seat having a restraining belt which passes through an opening in a back-rest of the seat, a belt guide movable relative to the opening, and means for securing the belt guide in position, whereby the restraining belt is adjustable to take account of the size of the child. According to a second aspect of the invention there is provided a system for relaxing the tension in the harness of a car safety seat for a child, wherein the back-rest of the seat has an opening through which a shoulder belt of the harness may extend, the belt passing over an adjustment member which has a first, tensioning position in which the belt is constrained to follow a longer path, and a second position in which the belt follows a shorter path, the adjustment member being made to occupy the first position when a car seat belt is used to retain the safety seat in a vehicle, and being free to move into the second position when the car seat belt is removed from engagement with the safety seat. According to a third aspect of the invention there is provided a safety seat having a contour adjuster comprising a panel pivotable from a position in which it spans a depression in the base of the seat to accommodate a smaller baby into a position overlying an adjacent portion of the seat to accommodate a larger baby or child. This third aspect of the invention may have utility in other types of seat used for babies and small children. In the drawings: Figure 1 is a perspective view of a car safety seat incorporating a first embodiment of harness adjustment system with the parts arranged for in-car use, Figure 2 is a perspective view of parts of the harness adjustment system viewed from the front, Figure 3 is a vertical section illustrating the harness adjustment system with the parts in three different positions, Figure 4 is a view of the seat from the front and side, partly broken away, to show the paths taken by the harness belts, 4 Figure 4A shows a union bracket of the harness , Figure 5 is a view similar to Figure 1 of a car safety seat incorporating a second embodiment of harness adjustment system as well as a comfort adjustment mechanism, Figure 6 is an exploded perspective view of the parts of the second harness adjustment system, and comfort adjustment mechanism, Figure 7 is a rear view of a cover or cowl forming part of the system shown in Figure 5 , Figure 8 is a front view of the locking plate of the system shown in Figure 5, Figure 9 is a side view of the locking plate taken along its axis, Figure 10 is a section through the cowl and locking plate taken on the line 10-10 in Figures 7 and 8, Figure 11 is a section through part of a comfort cam follower of the system shown in Figure 5, Figure 12 shows the locking plate in a relaxed position relative to the cowl , Figure 13 shows the locking plate in a disengaged position, Figure 14 is a diagrammatic side view of the seat to show a contour adjustment flap in a position for larger babies, Figure 15 is a view similar to Figure 15 but showing the contour adjustment flap positioned for smaller babies, Figure 16 shows the path followed by the belt through the contour adjustment flap and the manner of fixing the latter. Referring to Figure 1, a child's car safety seat comprises a shell 1 which may be injection moulded from a suitable polymer and padded and covered in fabric on its inner side. The shell has a surrounding rim 2 to which is pivoted a handle 3 shown in its forward position and capable of being moved rearwardly into a substantially upright carrying position, and then further rearwardly into a stowed position in contact with the part of the rim indicated at 4. Herein, unless the context otherwise requires, references to forward and rearward directions relate to the direction in which the child faces. In its forward position the handle braces the child's car safety seat (which faces rearwardly) against the back of the passenger seat on which it is supported. The seat is prevented from sliding off the seat by the conventional car seat belt which is looped around the back rest of the child's seat. The shell is supported on the base by a parallelogram linkage comprising arms 6 and 7. The arms 6 are biased in the counter-clockwise direction as viewed in Figure 1 so that the shell is resiliently supported relative to the base for a swinging or bouncing movement. Latches associated with the arms 6 serve to lock the shell to the base and prevent such movement when the arm is moved into its rearward, stowed position. Referring now also to Figures 2 , 3 and 4 the seat is provided with a harness including a pair of parallel shoulder belts 20 which extend through openings in the back rest and are linked to a crotch or lap belt 20a which passes through an opening in the bottom portion of the seat shell. A problem with seats of this type is that the position at which the shoulder belts are arranged to pass through the back rest portion must allow for vertical adjustment in order to accommodate children of different heights. In accordance with the present invention, the back rest has a pair of laterally spaced, generally vertically extending slots 21. The slots diverge in the upward direction to take into account the fact that the neck of the child increases with height. Associated with each slot is a guide 22 through which a respective belt passes. The guide is in the form of a plug and is received in a locking member or plate 23. The guide may rotate relative to the locking plate so that the belt extends from the back-rest at an optimum angle. The plate 23 is formed with ratchet teeth 24 for cooperation with a rack including complementary teeth 25 formed on the rear surface of the shell or on a part fast with the shell. A pressure member in the form of a lever 26 extends from a rod 27 journalled at its ends in bearings fast with the shell. Cam members 28 are formed on the shaft. With the lever in the position shown in Figure 3A the cam members press both locking plates into engagement with the teeth 25 so as to secure the locking plate and harness guide in place. A latch 28 pivoted to the shell at 29 cooperates with the lever to hold it in this position. Raising the latch as shown in Figure 3B allows the lever to fall into the position shown in Figure 3C and release the locking plates which may then be adjusted vertically, and re-secured by raising the lever and latching it. The level of the shoulder belts relative to the back-rest may be infinitely adjusted as the child grows, so that it is possible to ensure that the belts emerge from the back-rest at the level of the shoulders. Moreover, because the slots 21 diverge, and the guides 22 may rotate, the belts are positioned at an optimum spacing and orientation relative to the shoulders, so as to hold the child safely in a crash condition. The courses followed by the shoulder belts 20 and crotch or lap belts 20a are shown in Figure 4, with a union bracket which may be used to connect them being shown in Figure 4A. The crotch or lap belt may be tensioned and held tight by a clamp 30 pivoted in brackets 31 on the rearside of the back rest. The seat may be rotated from the position shown in Figure 1 through an angle of 90° for the purpose of seating or removing a child. To perform this movement, the handle must be placed in the stowed position. In this position a latch cooperates with a part on the handle to secure the shell against swinging on the linkage. When the seat is turned into its travel position and the handle moved forwards to brace the seat the latch is released and the seat is free to swing. The seat described above is secured in position on a passenger seat of a vehicle with the child facing rearwards using a conventional seat belt which is secured to a fitting on the back of the shell. The system for adjusting the harness described above may be incorporated into forward facing safety seats. The seat to be described with reference to the remaining figures 8 of the drawings uses the fitting which receives the conventional seat belt to operate a comfort adjustment mechanism of a rearward facing safety seat shortly to be described. Referring now to Figure 5, the child's car safety seat shown therein has a simpler base construction. The seat shell 101 incorporates a pair of forwardly extending support ribs 105 on which the seat may rest, and between which pass the parallel belts 120, 120a of the harness. The shoulder belts 120 are connected at their forward ends to the crotch or lap belt 120a which is passed back between the belts 120 and through a clamp 130 to allow the harness to be tensioned. The arrangement of the belts is generally as shown in Figure 4. The harness adjustment system incorporates a comfort adjustment mechanism in accordance with a second aspect of the invention. The comfort adjustment mechanism may be used in seats which utilise other systems for adjusting the harness. The conventional seat belt A of the vehicle is used both to retain the child's safety seat in position and also secure the harness in its desired position with a tension appropriate to in-car use. When the seat belt A is disengaged, tension in the shoulder belts 120 of the harness is relaxed and their adjustment made possible. Fundamentally, the harness adjustment system of the seat shown in Figure 5 corresponds to that of Figure 2 , and is depicted in an exploded view in Figure 6. As before, the rear side of the back-rest is provided with a pair of toothed racks, indicated at 125, formed on a plate rivetted to the back-rest. Generally vertically extending and diverging slots 221 pass through the plate and the back- rest. Guides in the form of plugs 222 are slidable in the slots 221 and are retained rotatably in openings in a single locking member or plate 223 having holes into which the plugs 222 are fitted. The central part 223a of the locking plate is rigid and edge portions 223b are resilient, being biased away from the racks 125. The plugs have nibs and the holes are so shaped that the plugs may be inserted and rotated into positions from which they cannot become detached from the locking plate. This construction therefore also possesses the advantages of minimal incremental adjustment and optimum spacing and orientation of the belts. The locking plate has formations along both vertical side portions 223b to cooperate with the rack 125. A pressure member or plate 229 is mounted on a spindle 231 provided with cam surfaces 234 indicated in Figure 8. Certain of these cam surfaces are positioned to bear on the central part 223a of the locking plate 223, whilst others bear on concavely shaped bearing surfaces 232 of a support 233, referred to herein as the comfort cam follower, and complementary bearing surfaces on the back-rest engage the spindle. The comfort cam follower 233 is secured to the shell 1 by pop rivets 234. The spindle 231 is also provided with further cams 234a positioned to make contact with the edge portions 223b of the locking plate. The comfort cam follower includes a rearwardly directed arm 233a shown in Figure 11 which is capable of flexing to allow the bearing surfaces to move through about 15". The bearing surfaces of the comfort cam follower and the cams 234a of the pressure plate which cooperate therewith are so shaped that the comfort cam follower is 10 made to move upwards as it swings forwards towards the back rest of the seat upon rotation of the pressure plate. The outer surface of the curved parts 232 of the comfort cam follower serves to support and guide the shoulder belts immediately before they pass through the guides 222. As the pressure plate moves forwards into an advanced position, the comfort cam follower moves upwards and the path X followed by the belts is lengthened to increase the tension in them, and vice versa. The comfort cam follower thereby serves as an adjustment member for the belt. A cover or cowl 240 overlies the mechanism described above and has a transverse slot 241 through which the pressure plate 223 extends (the bearing for the pressure plate journals being located between the cowl and the seat shell, but the fingers 230 being located rearwardly of the cowl). The cowl includes a finger 242, around the sides and upper extremity of which is a slot 243. The fingers 230 have forwardly projecting flanges 235 which may pass through the slot, one on each side of the finger 242. The flanges 235 are cut back near their roots. The cowl has a receptacle 243 into which fit the brackets 131 of the clamp 130, the receptacle having an opening to allow passage of the end of the crotch or lap belt 120a where it emerges from the clamp. When the seat belt A is threaded between the fingers 230 and 242, as shown in Figure 5, the fingers 230 are pressed forwards and the pressure plate rotated in the clockwise direction as viewed in Figure 6. The cams 234 on the pressure plate spindle cause the comfort cam follower to rise into its advanced position and tension 11 the shoulder belts around a child in the seat. The flanges 235 on the fingers 230 prevent the seat belt A being inserted behind all three fingers and failing to actuate the mechanism to tension the belt around the child. When the seat belt A is slipped between the fingers 230, 242 it is retained within the cut-outs at the root of the fingers 230. When the belt is removed, the pressure plate 239 may move rearwards through about 15° as shown in Figure 12. The cams 234 on the pressure plate spindle cause the comfort cam follower to move rearwards and downwards into its retracted position, thereby allowing relaxation of the shoulder belts passing over the cam. With the seat belt A removed, the pressure plate may be made to pivot down through 90° as shown in Figure 13. The cam surface 234a allows the edge portions of the locking plate to resile and disengage from the racks. The cam surfaces 234 bearing on the central part 223a of the locking plate rotate into a position in which the force applied to the locking plate is reduced. The plate is held in position but may be moved by hand into a new position against the resistance provided by cam 234. As shown in Figures 14 to 16, a contour adjustment device includes a panel 300 of semi-rigid plastics covered in the same fabric as is used to cover the seat shell. The panel has lugs 301 which fit over studs located within recesses formed between the base 303 and sides 304 of the shell. The panel is movable about its pivots as indicated by the arrows between the positions shown in Figures 14 and 15. In the latter position the panel bridges over the depression between the seat bottom 303 and the back-rest 305, so as to allow a very 12 small baby to lie more-or-less flat in the seat. In the position shown in Figure 14, the panel overlies the forward part of the seat bottom, so that a larger child may sit normally in the seat. The panel has an opening 306 through which the crotch or lap belt 120a may be passed in the position shown in Figure 14. When the panel is in the Figure 15 position, the belt 120a passes directly through the opening in the seat bottom. Modifications may be made to the embodiments described above. Although it is preferred for the locking plates to engage with toothed racks, other formations capable of securing the belt guides in place may be employed. Although a pair of racks (or other formations) is preferred, a single one between the slots 221 may be used instead. Conceivably the pressure plate may have a single finger disposed between a pair of fingers on the cowl, or other arrangements employed to enable the seat belt A to press the locking plate 229 forwards. The invention may also be used to permit the adjustment and relaxation of a belt which passes diagonally across the child's body and passes through a single opening in the back-rest and a single opening in the seat bottom.

Claims: 13 CLAIMS 1. A car safety seat for a child, the seat having a restraining belt which passes through an opening in a back-rest of the seat, a belt guide movable relative to the opening, and means for securing the belt guide in position, whereby the restraining belt is adjustable to take account of the size of the child. 2. A car safety seat as claimed in claim 1, wherein the guide is associated with a locking member, and a pressure member is arranged to urge the locking member against a holding surface associated with the back-rest so as to retain the guide in a selected position. 3. A car safety seat as claimed in claim 2, wherein the pressure member bears against a tensioning member having a surface over which the belt passes , the tensioning member being movable between a retracted position and an advanced position, whereby tension in the belt is greater in the advanced position than in the retracted position of the tensioning member when the belt is used to restrain a child, means being provided for moving the tensioning member into its advanced position upon application of a car seat belt to the safety seat. 4. A car safety seat including a system for adjusting a harness relative to the back-rest of the seat, wherein the back-rest is provided with a pair of upwardly extending slots through which shoulder belts of the harness extend, the position at which each shoulder belt passes through a respective slot being determined by guides capable of being made fast with the back-rest. 14 5. A seat as claimed in claim 4, wherein the back-rest of the seat is associated with an upwardly extending toothed rack, and each guide may be made fast with the back rest by a locking member engageable with the rack; at least one pressure member having an engaged position in which the locking member is held in engagement with the rack, and a released position in which the locking member is free to move relative to the rack. 6. A seat as claimed in claim 5 , wherein the back-rest is associated with a pair of laterally spaced racks, a single locking member provided with both guides having formations to engage with both racks . 7. A seat as claimed in claim 5, wherein the back-rest is associated with a pair of laterally spaced racks, and each guide is associated with a respective locking member with formations to engage a respective rack. 8. A seat as claimed in claim 6, wherein the locking member is concealed within a cover. 9. A car safety seat including a retaining harness and a system for relaxing the tension in the harness, wherein the back-rest of the seat has an opening through which a shoulder belt of the harness may extend, the shoulder belt passing over an adjustment member which has a first, tensioning position in which the belt is constrained to follow a longer path, and a second position in which the belt follows a shorter path, the adjustment member being made to occupy the first position when car seat belt is used to retain the safety seat in a vehicle, and being free to move into 15 the second position when the car seat belt is removed from the safety seat. 10. A seat as claimed in claim 9 including first and second parts having fingers between which may be passed a conventional car seat belt, so as to urge the adjustment member into its first position. 11. A car safety seat having a contour adjuster comprising a panel having a first position in which it spans a depression in the base of the seat to accommodate a smaller baby, and being pivotable into a position overlying an adjacent portion of the seat to accommodate a larger baby or child. 12. A car safety seat for a child having a backrest provided with a pair of laterally spaced slots, belt guides slidable longitudinally of the slots, a toothed rack extending adjacent the slots, a locking plate engageable with the rack, a pressure member pivoted to the back-rest and arranged to bear against the locking plate, a cover enclosing the pivot of the pressure member, part of the pressure member extending through an opening in the cover and having a finger arranged adjacent a finger on the cover, said fingers defining between them a slot for receiving a car safety belt for retaining the safety seat, a belt tensioning member movable between a position in which it applies tension to the belts and a position in which it allows the belts to relax, whereby the seat belt biases the tensioning member into a position tending to increase the tension in harness belts passing over it.

Inventors: BARKER DERRICK JOHN MARTIN, BARKER, DERRICK, JOHN, MARTIN
Applicants: BARKER DERRICK JOHN MARTIN, TOMY UK LTD, BARKER, DERRICK, JOHN, MARTIN, TOMY UK LIMITED
Application year: 1999
Main classification: B60N2
IPC codes: B60N2