Seat belts, also known as safety belts, are safety devices designed to secure and restrain the occupant of a vehicle, preventing harmful movement during a collision or a sudden stop. The seat belt reduces the likelihood of death or serious injury in traffic collisions by (a) reducing the force of secondary impacts between the occupant and interior surfaces of the vehicle, (b) preventing the occupant being ejected from the vehicle in a crash, and (c) keeping the occupant positioned correctly for maximum effectiveness of airbags where provided.
Seat belts come in various types, including lap restraints or lap belts, sash belts or three point seatbelts combining the lap belt and the sash belt into a unitary device.
Lap belts fasten across the lap of the occupant. These were the earliest type of seat belt, and are still standard in passenger seats of airplanes. The full force of an impact is absorbed along a relatively small area across the waist of the occupant and may cause damage to internal organs. A “sash” or shoulder harness is a strap that goes diagonally over the vehicle occupant's outboard shoulder and is buckled inboard of his or her lap. The sash belt restrains the occupant over a larger area than the lap belt. The sash belt may attach to the lap belt tongue, or it may have a tongue and buckle completely separate from those of the lap belt.
The 3-point belt is similar to the combination of separate lap and sash belts, but is provided as a single unit. Like the separate lap-and-sash belt, in a collision the 3-point belt spreads out the energy of the moving body over the chest, pelvis, and shoulders.
In most road vehicles, the three point seat belt is now standard. It comprises a tough strip of material, typically woven nylon, which is fastened to the car below the height of the seat on one side of the passenger, and is wound onto a spring loaded reel or drum that is above shoulder height or at least is threaded over a pulley that is above shoulder height and then drawn down to a drum or real that takes up spare seatbelt. Typically, a buckle that is coupled to the seatbelt is pulled down, across the passenger, from the shoulder to the other side of the passenger near the passenger's waist, where it engages a clasp provided for that purpose. Typically, pressure on a release lever on the clasp, releases the buckle, and the drum winds the belt up. In some models, the seatbelt itself is pulled down and across the occupant and is shackled by a releasable rod or loop.
Such seatbelts restrain the seated passenger with a strap that crosses the thighs from where a fixed end of the seatbelt is fastened to the chassis on one side, through an eye of a slider that is provided with a buckle that is slid into and held by the clasp, and then up across the body and over the shoulder to the reel or pulley wheel.
On impact or sudden stopping, the reel jams and prevents the seatbelt from being pulled out further, and typically is configured to retract the seatbelt. Such seat belts are reliable, convenient, and easily implemented to restrain the passenger, and easily released to allow the passenger to exit the vehicle.
Seatbelts are mandated by law in many countries, for both front-seat and back-seat passengers of many vehicles. In some jurisdictions passengers in taxicabs and the like, are not required to wear seatbelts, but the safety advantages of so doing are nevertheless clear.
Until the 1980s, three-point belts were commonly available only in the front outboard seats of cars; the back seats were only often fitted with lap belts. Evidence of the potential of lap belts to cause separation of the lumbar vertebrae and the sometimes associated paralysis, or “seat belt syndrome”, led to progressive revision of passenger safety regulations in nearly all developed countries to require 3-point belts first in all outboard seating positions and eventually in all seating positions in passenger vehicles.
Most modern seat belts are stowed on spring-loaded reels called “retractors” equipped with inertial locking mechanisms that stop the belt from extending off the reel during severe deceleration. Seatbelts in many newer vehicles are also equipped with “pretensioners” and/or “Webclamps”. Pretensioners preemptively tighten the belt to prevent the occupant from jerking forward in a crash. Some systems also pre-emptively tighten the belt in fast accelerations and strong decelerations even if no crash has happened. Webclamps clamp the webbing in the event of an accident and limit the distance the webbing can spool out (caused by the unused webbing tightening on the central drum of the mechanism). These belts also often incorporate an energy management loop (“rip stitching”) in which the lower part of the webbing is looped and stitched with a special stitching designed to “rip” at a predetermined load, which reduces the load transmitted through the belt to the occupant, reducing injuries to the occupant.
As with adult drivers and passengers, the advent of seat belts was accompanied by calls for their use by child occupants, including legislation requiring such use. Generally children using adult seat belts suffer significantly lower injury risk when compared to non-buckled children. Nevertheless, it will be appreciated that three point seatbelts are standard fixtures that are appropriate for restraining adults of various shapes and sizes. They are, however, engineered for adults, and are thus typically too big for small children. Adult 3 point seatbelts are generally inappropriate for children since the lower strap crosses the stomach and is consequently uncomfortable and potentially dangerous, and the diagonal shoulder strap invariably misses the shoulder of a child, and interferes with his or her neck or head. However, if the seatbelt is positioned under the arm, the seatbelt rubs against the underarm and/or neck, and is uncomfortable. Positioning the seatbelt under the arm is also dangerous, in that both sections of the belt cross the lower abdomen, and an impact may cause the seatbelt to retract across the stomach, risking rupturing internal organs.
Many jurisdictions now advocate or require child passengers to use specially designed child restraints. Such systems include separate child-sized seats equipped with their own restraints and booster cushions or seats for use by children together with the adult restraints. In some jurisdictions children below a certain size are forbidden to travel in front car seats.
Child safety seats (sometimes referred to as an infant safety seat, a child restraint system, a restraint car seat, or ambiguously as car seats) are seats designed specifically to protect children from injury or death during collisions. Automobile manufacturers may integrate child safety seats directly into their vehicle's design. Most commonly, these seats are purchased and installed by consumers. Many regions require children of certain ages, weights, and/or heights to use a government-approved child safety seat when riding in a vehicle. Child safety seats provide passive restraints and must be properly used to be effective. However, many child safety restraints in countries such as Canada and the United States are not used properly. To tackle this negative trend, health officials and child safety experts produce child safety videos to teach proper car seat installation to parents and caregivers. Baby car seats are legally required in many countries, including the United States, to safely transport children up to the age of 2 or more years in cars and other vehicles.
Booster seats are recommended for children that are too big for baby seats, until they are big enough to properly use a seat belt without them. Some jurisdictions require booster seats to be used by law. Booster seats raise the child and allow the seat belt to sit firmly across the collar bone and chest, with the lap portion fitted to the hips. If the seat belt is not correctly positioned across the collar bone and the hips, it will generally ride across the neck and the stomach and cause internal injuries in the event of a collision. Booster seats also facilitate the child looking out of the window and since the child is more comfortable and has better vision, are generally accepted by children. Booster seats are required by law in the US, up to the age of 9 or a weight of 90 pounds (41 Kg).
However, booster seats are large and bulky devices. Where a back seat of a vehicle is sometimes used to transport adult passengers and sometimes for transporting children, the booster has to be removed and replaced. Booster seats are space consuming and their storage in the trunk of a vehicle, minimizes the amount of groceries and other goods being transported. They are an additional expense for grandparents and other occasional drivers of children. When renting cars, booster seats may need to be rented separately, which is an additional expense, tempting parents to economize. For these and similar reasons, booster seats are often not available when required.
Vertically challenged adults may feel uncomfortable sitting on a booster, as may shorter children being transported to social events attended by taller peers.
U.S. Pat. No. 3,136,579 to Hunter, is an early example of a booster seat that raise the child to allow him or her to look out of the windows, but is bulky and cumbersome.
U.S. Pat. No. 3,380,775 to Offenbacher describes another bulky booster seat solution.
U.S. Pat. No. 3,265,438 to Regan et al. describes a pneumatically inflatable seat that can be deflated for storage. Pneumatic solutions are complicated and unreliable, and this never really caught on.
U.S. Pat. No. 3,547,489 to Grieser and U.S. Pat. No. 4,231,613 to Jonasson describe booster seats that have side loops for engaging a seat belt. The devices are fairly bulky. They are designed for the more or less obsolete lap straps, but not for a three point seatbelts.
U.S. Pat. No. 4,291,915 to Cox describes a booster that doubles up as a suitcase and can be used for storing objects therein, going someway to overcome the inherent space requiring disadvantage of booster seats. The device described is somewhat complicated and therefore expensive to manufacture, and it is not really a practical storage solution for more than its straps.
U.S. Pat. No. 4,461,510 to Cunningham, titled “Childs safety device for vehicle” describes a booster with a strap that goes behind the child and engages the shoulder strap of a three point seat belt. The strap may be adjusted in effective length for different sized children, but the width of the seat is fixed, and the leg straps may not be comfortable for children that are significantly narrower than the booster seat. Additionally, the booster seat is fairly cumbersome.
U.S. Pat. No. 5,308,116 to Zawisa, describes a device that engages the shoulder strap of a three point seatbelt at an adjustable height suitable for smaller passengers. However, the system described therein is only suitable for outside seated passengers, whereas the middle seat is actually the safest for backseat passengers. Furthermore, although offering a solution for larger children, the lap engaging section of the strap will generally be too high for smaller passengers that are, nevertheless, too large for an infant seat.
U.S. Pat. No. 5,468,020 to Scime describes an auxiliary harness that engages the seatbelt and adapts it to the child. Scime's system is different from the typical booster that raises the child, but is nevertheless, fairly bulky and thus inconvenient.
U.S. Pat. No. 5,609,367 to Eusebi et al. describes an adjustable three point restraint system that is suitable for both children and adults. It is part of the vehicle and significantly increases manufacturing costs of the vehicle. It is not retrofittable to standard vehicles provided with conventional three point seatbelts.
U.S. Pat. No. 5,733,004 to Celestina Krevh describes a fairly simple compact device for adjusting the shoulder strap of a three-point seatbelt and making it appropriate for use by a child. The device is designed for use with a booster seat. The device described is fairly compact, but when used with a booster seat, the space required for the booster seat makes the solution bulky and cumbersome and inappropriate for occasional use.
U.S. Pat. No. 5,797,654 to Stroud describes a belt buckle/tether strap for use with a booster seat that combines the advantages and disadvantages of U.S. Pat. No. 4,461,510 to Cunningham and U.S. Pat. No. 5,733,004 to Celestina Krevh.
U.S. Pat. No. 5,845,967 to Kane and U.S. Pat. No. 7,066,536 to Williams describe other bulky booster and children's seats.
WO9700184 to Smith describes a safety belt restraint device that holds the lap belt down and has a flatter profile than the conventional booster seat. Two embodiments are described. The first one holds the belt down between the legs and over each leg separately. The second is a sort of tray that engages the seatbelt. It is appropriate for a child whose width is not much narrower than the tray. The pelvis of a smaller child will not be adequately protected.
U.S. Pat. No. 7,703,806 to Bell et al. entitled “Seat Belt System for a Motor Vehicle” describes a system for adjusting the shoulder strap to the height of the passenger. However, the lap strap remains configured to the width of an adult and is thus inappropriate for use by smaller children as it risks damage to a narrow pelvis in impact.
USSN 2012/0019033 to Kelly describes an inflatable booster. By deflating the device, it may be stowed without significantly filling storage resources needed for luggage, groceries and the like. However, as described hereinabove with reference to U.S. Pat. No. 3,265,438 to Regan et al., the inflatable system is not really practical for occasional use, by grandparents and the like. Some adults are fastidious about using the mouth nozzle to inflate a booster seat, not knowing who previous users were. Inflatable seats may take two or three minutes to inflate, and require good lungs, and are thus problematic for many people such as asthmatics, the elderly and heavy smokers, for example. Additionally, the deflated seat itself takes up space.
CZ 2007,466 describes yet another booster seat.
Despite the plethora of developments in safety harnesses and boosters, there remains a need for a compact alternative to traditional booster seats for adapting a three point adult seat belt for use by smaller passengers. Embodiments of the present invention address this need.