Device for shortening brake activation reaction time

Abstract

The invention provides an under-thigh support and restrainer for use in combination with a driver's car seat. The device is made in the form of a triangular pillow that is attached to the car seat cushion and supports the driver's leg in a position required for the minimal time needed to move the driver's foot from the accelerator pedal to the brake pedal at the moment of danger. The pillow is provided with straps that can be wrapped around the driver's right thigh to restrain the driver's leg in the aforementioned position to allow minimal time for reaching the brake pedal.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to ergonomics, in particular to ergonomics of a vehicle driver as a biomechanical system. More specifically, the invention relates to a combination of a car seat with a thigh-movement restraining means and an under-thigh support for use by a driver of a vehicle in order to shorten brake activation reaction time and to reduce fatigue.

BACKGROUND OF THE INVENTION

[0002] Car crashes now claim more than 40,000 lives each year in the United States, a number that has slowly declined from about 50,000 per year over the last four decades. Automobile crashes are the leading cause of death among people 1 to 34 years of age, accounting for 3.4 million nonfatal injuries annually and costing an estimated 200 billion dollars. Rates of automobile fatalities and injuries per driver and per mile driven have decreased substantially because of safer cars and roads, laws that discourage drunk driving, and other measures, but the absolute toll of automobile crashes remains high.

[0003] By the year 2025 thirty three million people will be 70 years or older in America. This segment of the population will grow 2.5 times as fast as the total population and will comprise the largest percentage of "slow-reaction" accidents. Slowly but surely, senior citizens have developed a higher accident ratio than teenagers. Also, by 2025, total costs for motor vehicle accidents in the United States will exceed 450 billion dollars.

[0004] It took several decades to install seatbelts in cars. The auto industry at the time believed that safety would not sell and that emphasis on safety features would scare the public.

[0005] Advertising generally focused on comfort, style, and performance. At the same time, efforts to reduce traffic crashes never focused on the automobile but rather on the driver or the road.

[0006] When driving a vehicle, the driver's leg that controls the accelerator and brake pedals can be considered as a biomechanical system, the model of which is shown in FIG. 1. In the context of the present invention, the part of the leg from the fulcrum point H of the heel on the vehicle floor to the knee joint KN is referred to as "leg" L; the part of the driver's leg from point H to the point T1 of contact with the accelerator pedal 20 is referred to as "foot" FT; and the part of the driver's leg from point KN to the pelvic floor joint PF, which is considered to be the fulcrum point on the vehicle seat 22, is referred to as "thigh" TH. FIG. 2 is a view of the driver's right leg in the direction of arrow A in FIG. 1. Two planes are taken into consideration to analyze the movement in which the driver's leg participates. The first plane is plane I-I which is slightly inclined with respect to vertical plane V-V and passes through the thigh TH and leg L, i.e., the plane that passes through the joints PF, KN, and H' (where H' is a heel joint [FIGS. 1 and 2]). Plane I-I corresponds to the unrestrained position of the leg during normal driving with the foot PT on the accelerator pedal 20. The second plane is plane II-II that passes through the same joints when the foot FT is on the brake pedal 24. The position of the leg in plane II-II is shown by broken lines.

[0007] Let us consider the movements of the driver's leg when driving a car with an automatic gear box wherein two pedals, i.e., the accelerator pedal and the brake pedal, are used to control the car. Although these movements are more complicated in reality, in a simplified form they may be considered as the following two modes. Let us assume that the initial position of the leg is with the foot FT on the accelerator pedal 20. When braking is necessary, the driver with relatively short legs first slightly raises the foot FT from the floor F so that the heel is disconnected from point H and the leg is shifted sidewise to the brake pedal 24. In this movement, the entire leg is raised as a fulcrum relative to the point PF. The driver then turns the entire leg relative to plane I-I to plane II-II and moves it down in order to press on the brake pedal 24.

[0008] In the second mode, which is more typical of a driver with relatively long legs, the driver merely turns the foot FT relative to the point H in order to brake from the position on the accelerator pedal 20.

[0009] In reality, the aforementioned movements are more complicated and may comprise a combination of both movements simultaneously. In the context of the present patent application, movement of the foot from the accelerator pedal to the brake pedal also includes the movement of pushing on the brake pedal until actual initiation of the brakes, i.e., to the moment when the brake lights are ignited.

[0010] It is important to consider the aforementioned movements with regard to the time of braking. The inventor has experimentally proven that when a human being accomplishes braking movements on the basis of subconscious reflexes, the aforementioned movements are not at all optional. In other words, there exists a certain unnatural position of the pedal-controlling leg that can provide a more optimal breaking condition, i.e., the condition that allows the shortening of braking time and hence of the braking path.

[0011] Heretofore many studies have been conducted to improve the ergonomics for a vehicle driver. For example, "Survey of Auto Seat Design Recommendations for Improved Comfort" by M. P. Reed, et al. (University of Michigan, Transportation Research Institute, Ann Arbor), 1994 contains a review of a large body of literature with emphasis on fit parameters related to anthropometric measurements, feel parameters, including pressure distribution and vapor permeability, and support parameters defined with respect to seating posture. Particular attention is given to appropriate lumbar support configuration.

[0012] U.S. Pat. No. 6,170,355 issued in 2001 to W. Fay, III discloses an easily adjustable foot-operated pedal assembly, such as a brake pedal for use in heavy equipment, that can be placed in multiple positions to accommodate people of differing heights and body shapes.

[0013] U.S. Pat. No. 7,051,613 issued in 2006 to Burton, et al, discloses an adjustable pedal assembly for a vehicle that includes an adjustment bracket adapted for mounting on a vehicle, and the adjustment bracket includes a pair of outwardly extending side portions having a vertically extending arcuate slot. The adjustable pedal assembly also includes a pedal arm pivotally attached to the adjustment bracket using a pivot pin, such that an end of the pivot pin is slidably disposed within the arcuate slot in the adjustment bracket. The adjustable pedal assembly further includes a pedal pad mounted to the pedal arm and a pedal adjustment mechanism operatively attached to the pedal arm for adjusting the position of the pedal arm along a predetermined path such that the pivot pin is slidably positioned in the arcuate slot relative to the predetermined path of the pedal arm in order to ergonomically position the pedal pad.

[0014] U.S. Pat. No. 7,077,476 issued in 2006 to McMillen relates to an ergonomic weight support device for a driver's or a passenger's seat. Among other elements of the seat carcass attention is drawn to a thigh support. However, the main emphasis of this patent is on development of a universal ergonomic support that occupies less space, costs less to manufacture and install, simplifies manufacture, decreases needed components, and uses a more robust mechanism for supporting the weight of a human passenger.

[0015] The necessity for raising an under-thigh support is mentioned in many advertisements of modern cars. For example, in "Nissan 350Z GT--MotorBar Road Test" it is stated that "a raised bolster in the middle of the seat cushion helps give extra under-thigh support for more precise operation of the pedal." In the pamphlet titled "Follow-Up Test: 2006 Jeep Grand Cherokee SRT8" it is stated that "the long-haul comfort is commendable too, with excellent under-thigh support and feeling of the seats wrapping around."

[0016] However, all of these under-thigh support means relate to ergonomically profiled seats and do not provide positive and adjustable means for finding and securing a position of the leg most optimal for shortening reaction time from the moment the driver sees a danger to the moment of pressing on the brake pedal.

SUMMARY OF THE INVENTION

[0017] It is an object of the invention to provide a combination of a car seat with an under-thigh support for shortening brake activation reaction time and for reducing the driver's fatigue. It is another object to provide an under-thigh pillow for a driver of a vehicle that can be placed in the position most optimal for shortening brake activation reaction time. A further object is to provide the aforementioned under-thigh pillow with means for securing the pillow in an appropriate position on the driver's seat and for securing the driver's leg in the position required for minimal braking time. Still another object is to provide an adjustable under-thigh support that is built into the driver's seat.

[0018] The present invention provides an under-thigh support and restrainer for use in combination with a driver's car seat. According to one embodiment of the invention, the device is made in the form of a pillow having a flat lower surface that during use is maintained in contact with the surface of the seat cushion and an upper thigh-supporting surface which in the working position is tapered in the direction from the edge of the seat cushion toward the driver and is used for supporting the driver's thigh and hence the driver's leg in the position required for minimal time from detection of danger to activation of the brakes. The device is intended not only for comfortably supporting the driver's right leg in the aforementioned position but also for maintaining the leg in this position by using restraining means such as snaps, hooks and loops, and, in particular, hook- and loop-type fasteners which are commercially available under the trademark Velcro, or other fasteners that can be easily and automatically disconnected from the leg in case of emergency. The under-thigh pillow of the invention may have the aforementioned hook and loop fasteners on the lower surface if the seat cushion is not made from leather but rather from a material that can be easily engaged with such fasteners. If the seat cushion is made from leather or another smooth material with a low coefficient of friction, the triangular pillow can be used in combination with a seat cushion case that can be easily placed onto the seat cushion and can be made from a material that can be engaged with the Velcro-type straps so that the pillow with the restraining straps can be attached to the cushion case in the position most optimal for shortening the braking time. According to still another embodiment, the under-thigh support pillow is built into the driver's seat and can be maintained in the seat cushion in a hidden position inside the seat cushion with the upper surface of the pillow in the same plane as the surface of the cushion or can be raised to the aforementioned position most optimal for the specific driver with regard to his/her weight, height, and posture. In addition to the functional features associated with optimal conditions for braking, the under-thigh pillow reduces muscle strains and driver fatigue.

BRIEF DESCRIPTION OF THE INVENTION

[0019] FIG. 1 is a side view on the driver's leg as a biomechanical system.

[0020] FIG. 2 is a view in the direction of arrow A in FIG. 1.

[0021] FIG. 3 is a three-dimensional view of an under-thigh pillow in accordance with one embodiment of the invention.

[0022] FIG. 4 is a three-dimensional view of the under-thigh support pillow of FIG. 3 installed in a working position on the car seat cushion without the use of restraining strips.

[0023] FIG. 5 is a three-dimensional view of the under-thigh support pillow of FIG. 3 installed in a working position on the car seat cushion with the use of a car seat cushion case.

[0024] FIG. 6 is a sectional view of the car seat with a built-in under-thigh support pillow of the invention and with a mechanism of the invention for adjusting positions of the under-thigh support pillow.

DETAILED DESCRIPTION OF THE INVENTION

[0025] A three-dimensional view of the device made in accordance with one embodiment of the invention is shown in FIG. 3. It can be seen that this device comprises an under-thigh support pillow 30 that is intended for use in combination with a seat cushion of a car seat (not shown in FIG. 3) in order to support the driver's leg and preferably to restrain the driver's leg in a position most optimal from the viewpoint of shortening the brake activation reaction time.

[0026] A pillow body 32 has a flat contact surface 34 that during use of the device is maintained in contact with the surface of the seat cushion 36 (a three-dimensional view of a car seat 38 shown in FIG. 4) and an upper thigh-supporting surface 40, which in the working position of the device, is tapered in the direction from the edge 42 (FIG. 4) of the seat cushion 36 toward the driver (not shown) and is used for supporting the driver's thigh and hence the driver's leg in a position required for minimal braking time.

[0027] In the embodiment of FIGS. 3 and 4, means for securing the thigh-supporting pillow 30 to the seat cushion are made in the form of friction strips 44, 46, and 48. These strips comprise hook-and-loop fasteners which are commercially available under the trademark Velcro (hereinafter referred to as fasteners). Such fasteners are suitable for securing the pillow body 30 only when the car seat cushion is made from a material with a high coefficient of friction such as a rough fabric, which can be engaged with fasteners. A pair of Velcro straps 50 and 52 with mutually engageable surfaces on their ends are intended for wrapping around the driver's thigh in order to fix it in the aforementioned, optimal thigh-supporting position.

[0028] It is understood that strips 44, 46, and 48 are not suitable for seat cushions covered by leather or a similar material having a low coefficient of friction. In order to use the under-thigh pillow 32 on leather seats, the triangular pillow can be used in combination with a seat cushion case 54 of the type shown in FIG. 5. The seat cushion case 54 can be made from a material that can be easily engaged with the Velcro strip 56, or a Velcro strip 56 can be permanently attached to the area of the seat pillow case that corresponds to the position of the pillow 30. The seat cushion case 54 may have back straps 58 and 60 that go behind the seat cushion 36 to secure the seat cushion case 54, and the ends of the back straps can be tightened and tied, e.g., with Velcro fasteners 58a and 60a or snaps, etc. The lower edge of the cushion case 54 can be trimmed with a rubber cord 62 to secure the lower end of the cushion case 54 on the seat and to tightly embrace the surface of the entire seat cushion with the material of the cushion case 54.

[0029] According to another embodiment of the invention, the under-thigh support pillow can be built into the structure of the car seat to mechanically raise the pillow to the working position. For example, a simple mechanism 64 shown in FIG. 6 in a cross-sectional view of the car seat 66 can be used for shifting an under-thigh support pillow 68 between the position withdrawn into the seat cushion 70 shown in FIG. 6 by solid lines and the raised position of the pillow 68 shown in FIG. 6 by broken lines. In this embodiment, the upper surface 68a of the pillow 68 faces outward and is maintained substantially in the plane of the seat cushion 70 when the pillow 68 is in the withdrawn position. The pillow 68 may have any appropriate shape but preferably should have a triangular cross section where in the withdrawn position of the pillow the aforementioned upper surface 68a of the pillow 68 functions as a support surface for the thigh. The pillow is pivotally supported on an axle 72 that is installed in the innermost apex of the triangular cross section of the pillow so that the pillow 68 can be raised and lowered by rotating on the axle 72. These rotary motions are carried out with the use of a mechanism formed by a link 74, one end of which is pivotally attached to the pillow 68 by means of a pin 76, while the other end thereof is pivotally attached to a nut 78. The latter engages a screw 80 which is rotatingly supported in frame 82 of the car seat 66. The outer end of the screw that projects from the car seat supports a handle or a knob 84 located in the position easily reachable by the driver's hand.

[0030] By rotating the knob 84, it is possible to raise the under-thigh pillow 68 from the position shown in FIG. 5 by solid lines to the position shown by broken lines.

[0031] The pillow may have any suitable shape provided that the upper surface thereof can be arranged at an angle to the upper surface of the seat cushion tapering down from the door side to the central part of the seat cushion. The interior of the under-thigh support pillow can be stuffed with a sponged plastic or fabric, or the interior may contain an inflatable structure. The pillow body can be stuffed with the same foam plastic that is used for filling conventional car seat cushions.

[0032] The outer surface of the pillow of the invention is coated with a non-slip material, such as, e.g., one known under the trade name "Snugtex" (NFA Corporation, MA) which will work on all sorts of fabric and leather materials without slippage of the pillow when a person is driving without use of the aforementioned Velcro strips.

[0033] Investigations show that the total stopping distance of a vehicle is made up of four components: human perception time, human reaction time, vehicle reaction time, and vehicle braking capability.

[0034] Human perception time is the time it takes for the driver to see the hazard and for the brain to realize it is a hazard requiring immediate reaction. This component of stopping distance is a human factor and, as such, can be affected by age, tiredness, alcohol, fatigue, and concentration levels. Once the brain realizes danger, the human reaction time is the time it takes to move the foot from the accelerator to the brake pedal and then to depress the pedal. The movement time from the accelerator to the brake is approximately 500 ms (according to the University of Iowa).

[0035] When the under-thigh pillow 30 or 68 of the invention is placed onto the car seat cushion or raised into the working position, which is shown in FIGS. 4 and 5 and by broken lines in FIG. 6, and in which the driver's right leg assumes the above-described position and is fixed in the position that ensures the shortest brake activation time, then during driving the aforementioned brake response and activation time can be reduced by 50 to 150 ms, i.e., by 10% to 30% of the overall braking response time. For example, if a person is driving a car at 55 mph (88 km/hr), i.e., about 80.67 feet/sec. (27 m/sec.), the pillow saves 4 to 12 feet (1.3 to 4 m) before the brakes are even applied because it changes the geometry of the foot movement. More specifically, the pillow shortens the momentum required for the driver's foot to reach the brake pedal.

[0036] Here is another numerical example. A vehicle traveling at 65 mph (104 km/hr) covers 96 feet/sec. (32 m/sec.). Once the brain has recognized the need to brake, it still takes another half second or 48 feet (16 m), in some cases 650 ms or 62.4 feet (20.8 m), to initiate the braking action (essentially, to move the foot from the accelerator pedal to the brake pedal and to push on the brake pedal). The under-thigh pillow decreases stopping distance up to 30%, or up to 21 feet (about 7 meters), before the brakes are even applied (in some cases during testing the inventor herein got up to 41% between the results with and without pillow, especially for senior drivers). Moreover, the pillow reduces stress that is exerted on the lower back and right leg muscles.

[0037] It is understood that although, in general, the optimal position of the under-thigh support pillow will be common to various drivers of normal build, strictly speaking it may be individualized, especially for very slim or overweight people as well as for male and female drivers. Furthermore, the optimal position of the pillow should be relocated and readjusted when the driver wears different clothes, e.g., in winter and summer, etc.

[0038] Thus, it has been shown that the invention provides a combination of a car seat with an under-thigh support for shortening the brake activation reaction time and for reducing the driver's fatigue. The pillow can be placed into the position most optimal for shortening the brake activation reaction time. The pillow of the invention is provided with means for securing the pillow in an appropriate position on the driver's seat and for securing the driver's leg in the position required for minimal braking time. The invention also provides an adjustable under-thigh support that is built into the driver's seat.

[0039] Although the invention has been shown and described with reference to specific embodiments, it is understood that these embodiments should not be construed as limiting the areas of application of the invention and that any changes and modifications are possible, provided that these changes and modifications do not depart from the scope of the attached patent claims. For example, the pillow of the invention can be replaced by a raised portion of the car seat cushion. The pillow may have an inflatable structure. The principle of the invention for locating the driver's leg in the optimal position for shortening the brake reaction time is applicable for positions of the driver in vehicles for left-hand traffic as well as in vehicles with a non-automatic transmission, i.e., with a stick-shift control of speeds. In FIG. 6 the knob 84 is shown on the left side of the seat. However, depending on the construction of the seat, the knob 84 and the screw 80 may be located on the opposite side of the seat.

Claims

1. A combination of a vehicle driver's seat with an under-thigh support device for supporting the right thigh of a driver in a position that provides the shortest reaction time for movement of the driver's leg from the accelerator pedal to the brake pedal and for activation of the brake, wherein said vehicle driver's seat has a vehicle driver's seat cushion, said under-thigh support device comprising: an under-thigh support body having means for preventing sliding of said under-thigh support body on the surface of the vehicle driver's seat cushion and a support surface that is raised above the surface of the vehicle driver's seat cushion and is tapered in the direction from the right thigh of the driver towards the center of said vehicle driver's seat cushion for supporting the driver's thigh in said position that provides the shortest reaction time for movement of the driver's leg from the accelerator pedal to the brake pedal and for activation of the brake.

2. The combination of claim 1, wherein said means for preventing sliding is a surface with a high coefficient of friction relative to said surface of the vehicle driver's seat cushion.

3. The combination of claim 2, wherein said surface with a high coefficient of friction relative to said surface of the vehicle driver's seat cushion is formed by Velcro fasteners.

4. The combination of claim 3, wherein said under-thigh support body is further provided with automatically releasable restraining means for restraining the right thigh of the driver in said position that provides the shortest reaction time for movement of the driver's leg from the accelerator pedal to the brake pedal and for activation of the brake.

5. The combination of claim 4, wherein said releasable restraining means comprise at least a pair of strips attached to said under-thigh support body, said releasable restraining means having connecting elements on their ends and having a length sufficient to engage said connecting means in a position wrapped around the driver's right thigh.

6. The combination of claim 5, wherein said connecting elements are Velcro fasteners.

7. The combination of claim 2, wherein said means for preventing sliding is a vehicle driver's seat cushion case that can fit onto said vehicle driver's seat cushion, said vehicle driver's seat cushion case having strips for attaching said vehicle driver's seat cushion case to the vehicle driver's seat cushion and having at least a part of the surface of said vehicle driver's seat cushion case that can be engaged with said means for preventing sliding.

8. The combination of claim 7, wherein said means for preventing sliding and at least a part of the surface of said vehicle driver's seat cushion case comprise Velcro fasteners.

9. The combination of claim 7, wherein said under-thigh support body is further provided with automatically releasable restraining means for restraining the right thigh of the driver in said position that provides the shortest reaction time for movement of the driver's leg from the accelerator pedal to the brake pedal and for pushing on the brake pedal.

10. The combination of claim 9, wherein said releasable restraining means comprise at least a pair of strips attached to said under-thigh support body, said releasable restraining means having connecting elements on their ends and having a length sufficient to engage said connecting means in a position wrapped around the driver's right thigh.

11. The combination of claim 1, wherein said under-thigh support body is built into said vehicle driver's seat cushion, said combination further comprising a support moving mechanism for moving said under-thigh support body between a first position where said means for preventing sliding comprise a contact surface that coincides with the surface of said vehicle seat cushion and a second position where said contact surface is raised above said vehicle seat cushion and is tapered from the right thigh of the driver toward the center of said vehicle driver's seat cushion.

12. The combination of claim 11, wherein said support moving mechanism comprises: a pivot axis that rotatingly supports said under-thigh support body to said vehicle driver's seat; a rotatable handle attached to said vehicle driver's seat; and a mechanism between said rotatable handle and said under-thigh support body that is capable of moving said under-thigh support between said first position and said second position when said rotatable handle is rotated.

13. The combination of claim 12, wherein said mechanism comprises a screw rigidly connected to said rotatable handle, a nut engaged with said screw, and a link, one end of which is pivotally connected to said nut and another end is pivotally connected to said under-thigh support body.

14. The combination of claim 1, wherein said under-thigh support body comprises a pillow having a triangular shape.

15. The combination of claim 2, wherein said under-thigh support body comprises a pillow having a triangular shape.

16. The combination of claim 3, wherein said under-thigh support body comprises a pillow having a triangular shape.

17. The combination of claim 4, wherein said under-thigh support body comprises a pillow having a triangular shape.

18. The combination of claim 11, wherein said under-thigh support body comprises a pillow having a triangular shape.

19. The combination of claim 12, wherein said under-thigh support body comprises a pillow having a triangular shape.

20. The combination of claim 13, wherein said under-thigh support body comprises a pillow having a triangular shape.