Abstract:
This invention provides a child safety seat with an integral seat belt tensioner for properly securing the seat to the passenger seat of an automotive vehicle by taking up the slack in the seat belt after it has been fastened through the child seat. The tensioner pulls or pushes the seat belt so that the few inches of slack that usually exist are eliminated by the tensioner. The safety seat is adapted to have internal space, either in its back and/or below the seat, to accommodate the tensioner and the belt movement so that the controls, tensioner, and/or other moving parts are out of the reach of the a child in the seat. A preferred version of the tensioner includes motor and gearing to move a belt holder up and down generally along the rear of the safety seat, for tightening and loosening the belt, respectively.

Description:
[0001]     This application is a continuation of U.S. Non-Provisional application Ser. No. 10/308,069, filed Dec. 2, 2002, entitled “Child Automotive Safety Seat With Integral Seat Belt Tensioner,” issuing as U.S. Pat. No. 6,779,842 on Aug. 24, 2004, which claims priority of Provisional application Ser. No. 60/338,415, filed Nov. 30, 2001, entitled “Child Automotive Safety Seat with Integral Seat Belt”, which is hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention.  
         [0003]     This invention relates generally to child safety seats for use in an automotive vehicle and more particularly to properly securing a child&#39;s safety seat to a passenger seat of the vehicle.  
         [0004]     2. Related Art.  
         [0005]     Today&#39;s passenger vehicles have a seat restraint device, commonly known as a “seat belt,” for each occupant the vehicle is designed to carry. However, use of a conventional seat restraint by a small child can result in serious injury to the child in the event of a collision or other accident. To mitigate this problem, child safety seats and other devices have been developed which improve the safety afforded the child passenger. Such safety seats are typically secured to the vehicle&#39;s passenger seats directly by the vehicle&#39;s seat belts.  
         [0006]     Typically the driver and passengers sitting at the sides of the vehicle are provided with a restraint apparatus comprised of an integrated shoulder harness and a lap belt, sometimes termed a “3-point restraint system.” Occupants sitting in a center position often have only a lap belt. For the integrated shoulder harness/lap belt device of the 3-point system, the shoulder portion is normally attached to an inertial locking wind-up reel located in the vehicle&#39;s door pillar. The lap portion is attached to a fixed anchor near the floor of the vehicle adjacent to the door. The shoulder and lap portions are connected together as a continuous length upon which slides the male seat belt buckle. The vehicle&#39;s mating female buckle is typically attached to a short, upright supported belt section, also securely anchored to the floor of the vehicle but near the center of the vehicle.  
         [0007]     When the vehicle stops abruptly, the inertial reel locks up to restrain the occupant, however a few inches of belt are released prior to final lock up of the reel. This small amount of belt release is acceptable, in fact desirable, for an adult to minimize his or her injuries. However, this same small belt release is unacceptable when the belt is being used to secure a child safety seat.  
         [0008]     To maximize the child&#39;s safety, it is recommended that the child, in an appropriately sized child safety seat, always be placed in the center position of the rear seat of the vehicle. In this position the child&#39;s seat is secured with the lap belt and use of the 3-point restraint system is avoided. In this central position, the child&#39;s safety seat is secured to the vehicle by threading one end (typically the longer, male end) of the vehicle&#39;s seat belt through the appropriate slots in the safety seat and connecting this male end with the mating female end. Typically the loose, male end of the lap belt is pulled to tighten it.  
         [0009]     According to the Governor&#39;s Traffic Safety Committee of the New York State Department of Transportation: “The child safety seat should be attached as tightly as possible with the vehicle&#39;s safety belt. The seat should not move more than 1 inch toward the front of the car or side to side.” In the recommended rear, center seat position, it is very difficult for an adult to bend over and lean inward to grasp the loose end of the lap belt and then generate sufficient pulling force to satisfactorily urge the child&#39;s seat firmly down and rearward against the vehicle&#39;s seat back. Because of this difficult access by an adult to the rear, center seat position, only rarely is a child&#39;s safety seat properly and safely installed.  
         [0010]     A few inventors have addressed these problems. For example Smith (U.S. Pat. No. 5,579,561), issued Dec. 3, 1996, provides a seat belt gripping device for a 3-point restraint system that clamps and locks the shoulder portion and lap portion of a seat belt together to secure the child safety seat in place on the car seat. The device is tamper resistant so that children and infant seat occupants will not be able to remove the devices while they are in use. This device is designed to eliminate the need to remove slack from the shoulder portion of the seat belt to ensure that the child safety seat does not move in a forward direction during a sudden stop or collision. This device and others like it only addresses the removal of slack from shoulder harness type belts. It does not facilitate tightening the lap-type seat belt to achieve the recommend degree of firmness in securing the safety seat.  
         [0011]     Barley, et al. (U.S. Pat. No. 5,611,596), issued Mar. 18, 1997, specifically addresses the issue of inadequately tightened seat belts when used to secure child safety seats. Barley discloses a child safety seat with an integral seat belt tightening mechanism. Barley&#39;s seat comprises a seat body having a seat portion and a backrest portion. Guides on the seat body define a strap path for a strap of an adult seat belt to be used to secure the child seat body to a vehicle seat. A strap deflecting lever is movable between a first position clear of the strap path and a second position in which the strap is deflected and thus tightened. Although this design increases the degree of seat belt tightness, it has only two tension positions, a minimum and a maximum. It does not permit a continuous adjustment of the tension to assure that the recommended standards are developed. In addition, Barley&#39;s child seat is complex and would be expensive to manufacture when one considers its internal seat belt (strap) tightening mechanism. This mechanism also adds to the weight of the safety seat which makes its transportation and installation difficult.  
         [0012]     Koledin (U.S. Pat. No. 5,839,789), issued Nov. 24, 1998, discloses a seat belt tensioning device and a system for tightly positioning a child safety seat within the confines of a vehicle comprising a belt receiving member and a tensioning means for engaging the belt receiving member and tensioning the seat belt. Koledin shows some similarity to my invention, however, he introduces substantial reliability and cost questions by his incorporation of spring biased pinch clamps, pinch clamp release levers, fixed clamp stops, a split cylinder wind-up reel, cable guides, a tensioning knob, a worm drive, a worm gear and a torsion rod. In an alternative embodiment he introduces, but does not illustrate, a screw drive and cantilever arm in lieu of the split cylinder. The arm would pull the seat belt upward to increase its tension. Koledin also suggests operating his tensioning knobs and pinch clamps with an electric motor.  
         [0013]     Bello, et al. (U.S. Pat. No. 6,024,408), issued Feb. 15, 2002, takes a direct approach to assuring the proper installation of a child safety seat. Bello provides an auxiliary web belt that is wound around a drum of a winch. The winch is mounted on a pressure bar which is placed on a child safety seat after the seat is in position on the passenger seat, but before the child is placed in the seat. Fasteners at the ends of the auxiliary belt are attached to a vehicle seat belt that is not to be used for the child&#39;s seat. Alternatively, the fasteners may be directly attached to the vehicle&#39;s seat belt anchoring points. After this belt is properly anchored to the vehicle, the winch is actuated to tighten the belt thus pressing the child&#39;s seat into the passenger seat. After the child&#39;s seat is properly pressed against the passenger seat, the vehicle&#39;s unused passenger seat belt is passed through the openings provided in the child&#39;s seat and tightened to finally secure the child seat to the passenger seat of the vehicle. The winch is then released and the auxiliary belt, winch and pressure bar are removed. The child may then be placed in the properly secured safety seat. Bello&#39;s device would appear to be effective, but at the expense of having to attach and later remove a fairly complex, multi-component secondary device i.e. the auxiliary belt, the winch, and pressure bar in a moderately complex process.  
         [0014]     Therefore, it is a primary object of the extant invention to provide a device that eliminates the complexities and other shortcomings of the prior art while still assuring that child safety seats are properly positioned and tightened. It is a further object of this invention to provide a child&#39;s automotive safety seat with an integral seat belt tensioning capability that is easy and simple to use. It is an additional object of this invention to provide such a safety seat that is also robust and inexpensive to produce.  
       SUMMARY OF THE INVENTION  
       [0015]     This invention provides a child safety seat with an integral seat belt tensioner for properly securing the child safety seat to the passenger seat of an automotive vehicle. The invented seat belt tensioner is adapted to pull or push the belt, after the belt is buckled, to take up any slack that is in the belt. This pulling or pushing may comprise moving the belt upward and/or forward away from the seat, or may even comprise moving the belt sideways or downward. Preferably, the moving parts for pushing or pulling the belt, and the portion of the belt being pushed or pulled, is contained within the child safety seat, so that the tensioner is integrally provided in the safety seat and also out of reach of the child.  
         [0016]     This preferred embodiment comprises a seat frame with a mechanism contained therein for receiving the seat belt and for pulling it upwards generally vertically at the rear of the safety seat. The safety seat frame has left and right sides and a central rear interior space holding the tensioner. The preferred tensioner comprises a belt holder, preferably a tube or bracket, through which the seat belt is placed so that the belt passes from side to side across the back of the safety seat. The tensioner is adapted to raise and lower the belt holder, and therefore the belt, in response to actuation of a motor, a manual crank or other handle, or other actuation system.  
         [0017]     In one embodiment, each side of the seat frame includes a nominally vertically-disposed elongated slot and the belt holder comprises a generally horizontal hollow tube or other member that is moveable upward and downward in the elongated slots. The seat belt is conventionally attached to the vehicle, and one or more of the portions of the buckled seat belt pass through the tube. A mechanism is provided for slideably adjusting the movable tube within the slots. Adjusting the tube upwards, tightens the child&#39;s seat against the seat of the vehicle. Adjusting the tube downwards, releases the tension allowing the seat belt to be removed from the tube and the seat to be removed from the vehicle.  
         [0018]     The means for slidably adjusting the tube containing the vehicle&#39;s seat belt may be various manual or automated systems, but preferably includes a reversible motor and a gear assembly. The preferred gear assembly, operated by the electric motor in the preferred embodiment, comprises a speed reducing pinion gear/ring gear pair, a drive screw rotated by the ring gear, and a drive screw follower that rides up or down the length of the drive screw depending on the rotational direction of the motor. The drive screw follower is fixedly secured to the horizontally disposed belt receiving tube. Thus, as the electric motor is operated in one direction, the seat belt is pulled upward and thus tensioned, thereby safely securing the child&#39;s seat to the vehicle&#39;s seat. When the direction of the motor is reversed, the tension is released.  
         [0019]     These and many other features and attendant advantages of the invention will become apparent as the invention becomes better understood by reference to the following detailed descriptions and accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]      FIG. 1  is the child&#39;s safety seat according to one embodiment of the invention, as viewed from the back, with an embodiment of a belt adjustment tube in its lowered position.  
         [0021]      FIG. 2  is of the embodiment depicted in  FIG. 1 , but with the belt adjustment tube in its raised position.  
         [0022]      FIG. 3  shows the details of the gear adjustment assembly of one embodiment of the invention.  
         [0023]      FIG. 4  shows the details of the hand-powered gear adjustment assembly of an alternative embodiment of the invention.  
         [0024]      FIG. 5  is a schematic view of another embodiment of the invention.  
         [0025]      FIG. 6  is a schematic view of another embodiment of the invention wherein a cam-style tensioner is provided.  
         [0026]      FIG. 7  is a schematic view of yet another embodiment of a tensioner of the invention.  
         [0027]      FIG. 8  is a schematic view of yet another embodiment of a tensioner of the invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]     As shown in  FIGS. 1 and 2 , the preferred child automotive safety seat  1  comprises a child safety seat frame  10  having left and right sides, each side including a nominally vertically disposed elongated slot  15 . The invention further includes tensioner system  2  that comprises seat belt receiving tube  20  slideably received and moveably constrained within slots  15 . The safety seat  1  further includes means for slideably adjusting tube  20  within slots  15 . This means is operatively connected between frame  10  and tube  20 . In the preferred embodiment of this invention, means for slidably adjusting tube  20  includes reversible motor  32  and gear assembly  40 . Motor  32  receives electrical power from the vehicle and is reversibly controlled by electrical switch  50 . In the preferred embodiment, electrical power is provided by connecting switch  50 , via cable  52  and plug  54 , to the vehicle&#39;s accessory receptacle (not shown). For future Original Equipment Manufacture (OEM), it is anticipated that the vehicle will be pre-wired for the child&#39;s safety seat much like vehicles now are pre-wired for electrical seat adjustment.  
         [0029]     Referring now to  FIG. 3 , gear assembly  40  includes pinon gear  42  driven by motor  32  and operatively meshed with ring gear  44 . This assembly further includes drive screw  46  which is fixedly attached to the ring gear at its center of rotation. Drive screw follower  47  has first end  48  and second end  49 . The first end is operatively threaded onto drive screw  46  and the second end is fixedly connected to seat belt receiving tube  20 .  
         [0030]     The use and operation of this invention is exceptionally simple and robust. After placing safety seat  1  within the vehicle, the “long” portion of the vehicle&#39;s seat belt  100  is passed through belt receiving tube  20  and secured to the conventional buckle  110 . Switch  50  is then moved to its tightening position, thus energizing motor  32 . Energizing the motor rotates pinon gear  42  at a relatively high rate. Pinon gear  42 , engaging ring gear  44 , rotates it at a substantially reduced rate. Drive screw  46 , fixedly attached to the ring gear, thus rotates at the speed of the ring gear. As the drive screw rotates, follower  48  is driven up the length of the drive screw. Tube  20 , containing seat belt  100 , is thus pulled upward, being guided by the vertically disposed elongated slots  15  in frame  10 . In this fashion, as shown in  FIG. 2 , the child&#39;s safety seat is properly tightened against the seat of the vehicle (which is below and behind the safety seat but not shown in the Figures). Conversely, moving the switch to the release position, operates the motor in the reverse direction, causing the tube to be lowered and the tension in the belt to be released. The belt may then be disconnected from its anchor point and the seat removed.  
         [0031]     In the embodiment of  FIGS. 1 and 2 , the open ends  21 ,  22  of the tube  20  are at or near the outer side surfaces  11 ,  12  of the safety seat. This way, the parent or caretaker may easily reach the tube  20  and easily insert the seat belt portion  100  through the tube. If additional access is needed to easily insert the seat belt  100  through the tube, the tube and seat may be adapted so that the belt may be guided through the tube, for example, by making the seat rear surface open in the region of the tube for access to the tube, and making the tube rear side partially open so the belt may be accessed of guided through the tube from the rear of the seat.  
         [0032]     In alternative embodiments, the motor  32  may be eliminated and a hand operated means provided to rotate drive screw  46 . For example, as shown in the tensioner system  2 ′ of  FIG. 4 , gear  42 ′, which engages ring gear  44 ′, has axle  45  that extends to a hand-operated handle ( 51  in  FIG. 5 ). In addition, tube  20  may be upwardly curved, so that its center is higher than its ends, to minimize any potential for abrasion or development of stress concentration points on the seat belt where it enters and exits the tube.  
         [0033]     The materials used in this invention are selected to provide the necessary strength to each component to assure its full reliability, smooth operation, minimal or no maintenance, light weight, ease of manufacture and overall low cost. It is anticipated that in the preferred embodiment, frame  10 , tube  20  and gear assembly  40  will be formed from high strength plastics. It is also acceptable for additional strength to form tube  20  from a high strength metal such as a steel alloy. The materials used in the gear assembly are selected for their self-lubricating and non-galling properties (e.g. Teflon™, or Delrin™). As with conventional child safety seats, known means for securing the child into the safety seat are incorporated, as well as common methods of providing appropriate padding of the frame to assure the child&#39;s safety and comfort.  
         [0034]     Reversible motor  32  may be operated by the conventional 12VDC power provided in automotive vehicles. Its rotation speed is matched with gear ratios and the drive screw pitch of the gear assembly to provide a movement rate of tube  20  of about 10 inches per minute. Switch  50  is placed so that it is inaccessible to the child occupant of the seat (and any other child occupants in the vehicle).  
         [0035]     The dimensions of the components of this invention are selected to provide the same performance features as the materials and indeed are determined in concert with material selection. For example frame  10  is appropriately sized for the child anticipated to be supported by the safety seat. Tube  20  has an internal diameter just sufficient to easily pass a conventional seat belt through its length. For example, when seat belt portion  110  includes the male portion of the buckle, the tube  20  is sized to accommodate that buckle portion as well as the flexible portion of the belt. The lengths of slots  15  are nominally 5 inches and the drive screw follower has a similar range of motion along the length of the drive screw.  
         [0036]      FIG. 5  illustrates an alternative embodiment of the invented child safety seat  200 , which includes yet another embodiment of a tensioner  202 . This tensioner  202  is supported in the frame  10  by a horizontal brace  60  that is rigidly attached to the frame. The belt holder  220  is preferably a semi-cylinder with an open top side, into which the belt  100  may be placed. The ends of the belt holder  220  do not reach the sides of the frame  10  and do not extend through any slots in the frame. Preferably, only the belt  100  extends through slots  115  in the frame, so that no hard or sharp parts move in the slots, thereby, reducing the chance of fingers, clothing, or other items being caught in the slots during tightening of the belt. The belt holder  220  is raised and lowered, for example, by a manual handle  51  and gearing (collectively numbered  140 ), as discussed above. While the safety seat is shown with an open rear side for the sake of illustration, the safety seat&#39;s rear side may be substantially closed, except for a portal through which the belt-holder  220  and belt  100  may be accessed by the parent or caretaker when the seat is being installed in the vehicle.  
         [0037]      FIG. 6  illustrates another embodiment of a safety seat  300 , which uses a cam-style tensioner  302 . The cam  150  may be rotated by automatic or manual means (not shown) to a first position (in  FIG. 6 ) that tightens the belt by placing the cam long dimension generally vertical to lift the belt, or to a second position (not shown, generally 90 degrees from the first position) that loosens the belt by placing the short dimension of the cam generally vertical. The tensioner  302  may include retaining structure (not shown) for retaining the belt in proper position on the cam, whether the cam is in the first or second position.  
         [0038]      FIG. 7  illustrates another embodiment of a tensioner  402  that features a central push-member  403  forces the belt  100  downward between two supporting structures  404  to tighten the belt, and that lifts up from the belt to loosen the belt.  FIG. 8  illustrates another embodiment of a tensioner  502  that includes a cam-style member  503  that pushes the belt to the side against a structure  504  to tighten the belt. In  FIG. 8 , the cam-style member  503  is shown in pivoted into the tightening position, and is shown in dashed lines in the releasing position.  
         [0039]     It is noteworthy that the tensioners  402  and  502  in  FIGS. 7 and 8  utilize additional structure ( 404 ,  504 ) against which the belt is pushed or pulled to affect the direction of the belt movement and take up the slack. In the embodiment of  FIG. 7 , the combination of the central push-member  403  and the supporting structures may be considered the belt holder. In the embodiment of  FIG. 8 , the combination of the cam-style member  503  and the structure  504  may be considered the belt holder.  
         [0040]     Thus, there are various ways of moving the belt within the child&#39;s safety seat that take up the slack of the belt, including pulling/pushing the belt up or down, forward or backward, or sideways in a manner that removes the slack. Preferably, the belt may be easily threaded through or looped over the belt tensioning system, so that parent or caretaker may do so without using tools and without spending substantial amounts of time. Preferably, the belt does not wrap or wind on a spool or reel. Preferably, the belt does not wrap more than about ½ wrap around any part of the tensioning system, that is not wrap more than about 180 degrees.  
         [0041]     Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims.