AU2010214666A1

AU2010214666A1 - A mechanical velocity change sensor and recorder

Info

Publication number: AU2010214666A1
Application number: AU2010214666A
Authority: AU
Inventors: Don Sweetman
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-08-26
Filing date: 2010-08-26
Publication date: 2011-03-17

Description

1 A MECANICAL VELOCITY CHANGE SENSOR AND RECORDER [001] This invention relates to a recording device which is able to detail the speed and direction of a vehicle involved in collision with a stationary object or another vehicle. 5 [002] In particular this invention relates to a very unique apparatus which is able to be mounted to a vehicle so as to determine the magnitude of speed and also the direction of impact of such vehicle if involved in a collision. [003] There are already a variety of speed sensors and recorders adaptable to be placed or included as part of a motor vehicle to determine the magnitude of 10 the speed of the vehicle prior to the collision. [004] For example more recently as part of an automobile's electronic system sensing devices have been included that link to the car's instrumentation so as to be able to detail velocity and even in some cases the direction the vehicle was travelling at impact. 15 [005] The problem with the electronic systems however is that they need to be maintained through the use of a battery or in some cases while they may be charged by other instrumentation within the vehicle such communication could often be lost or fail to be transferred when the car is involved in a collision. [006] As the person skilled in the art will appreciate, that while electronic 20 systems provide advanced logic to provide accurate information, the device itself often becomes inoperable and dysfunctional once the vehicle has become involved in a dramatic impact. [007] Hence the main purpose of the impact apparatus provided for in this invention would be to provide such a device that would still be able to have the 25 means of measuring the minimum speed of a vehicle involved in a collision with 2 a stationary object or another vehicle responsible for arresting the motion of said vehicle. [008] To do this a more mechanical device would be required. [009] Hitherto there have been various sensors and recorders which use 5 simplistic mechanical arrangements that for the most part comprise a sensing mass constrained by a spring to an initial position in which it remains until it is acted upon by a sudden jolt or impact of the vehicle-when it is involved in a collision or similar such event. [010] The magnitude of the impact can be determined by recording the 10 changes in position of the sensing mass from its initial position after and before the crash. [011] For the most part these mechanical systems involve a spring and mass arrangement wherein the spring and mass system is initially deflected from its original position upon impact. It is the degree of deflection which then can be 15 mathematically manipulated to facilitate the actual speed measurement. [012] Nonetheless a problem with these acceleration mechanical sensor arrangements is that they are for the most part only uni-directional. [013] As the person skilled in the art will appreciate that given the main sensing device is uni-directional, accurate readings based on deflection of the 20 spring mass system will not be possible if the vehicle slews from a direction of front-on impact with a stationary object or another vehicle. [014] Hence as can be seen if the vehicle is driving along in a forward direction using the conventional spring mass system deflection will take place proportional to speed changes in the vehicle only in the case when it is a direct 25 frontal impact.

3 [015] As the vehicle begins to slew from its forward direction which is quite normal during sudden braking and the like of the vehicle, the actual sensor is no longer aligned with that point of impact so the deflection recorded will not appropriately indicate the actual speed at which the vehicle was travelling. 5 [016] Not only will there be inaccuracies in the measuring of the minimum speed of the vehicle involved in the collision using the conventional uni directional impact apparatus, there will also be no recording or detail of the direction the vehicle was travelling at impact. [017] During accident investigations not only is it useful to have information 10 with respect to the actual speed the vehicle was travelling but also possible description as to the direction the vehicle was travelling at impact which may in many cases assist in determining the cause of the accident. [018] Therefore there clearly remains a need in the relevant art to provide an apparatus which can still sense and record changes in the velocity or speed of a 15 vehicle involved in a crash using traditional mechanical means but at the same time if these conventional mechanical spring mass systems are to be employed, they are still required to provide appropriate accurate information of speed even in the case where the vehicle has slewed off a direct impact with the colliding entity. 20 [019] It is therefore an object of this invention to provide a vehicle magnitude and multidirectional impact apparatus for measuring both the speed and direction of a vehicle involved in the collision with a stationary object or another vehicle. [020] Accordingly in one form of the invention there is provided a vehicle 25 magnitude and multidirectional impact recording apparatus, for the measuring-of the speed and direction of a vehicle involved in a collision with a stationary object or another vehicle, said apparatus including, 4 [021] a mainframe, [022] said frame adapted to support a spring and mass unit which is able to rotate through an arc of 180 degrees, [023] said spring and mass unit including a movable weight in combination with 5 a spring member, [024] said movable weight adapted for relative movement against or from spring member for a compression or extension of the windings of said spring member when the motion of the vehicle is arrested through impact, [025] such that when the vehicle becomes involved in an impact or collision 10 and said vehicle has slewed off a direct travel impact projection, [026] said spring and mass unit rotates such that the spring and mass unit maintains its original orientation of direction of vehicle travel so that the spring and mass unit is correctly aligned for an accurate indication of vehicle impact speed recordable from the relative extension or compression of the spring 15 member against the original position of the movable weight. [027] In preference the vehicle magnitude and multidirectional impact apparatus further includes a scriber which is connected to the movable weight, said scriber adapted to mark out upon a recording surface in contact with the scriber as part of the impact apparatus, such that as the vehicle slews off direct 20 forward vehicle travel direction, the relative markings of the scriber on the recording surface can identify the direction in which the vehicle was travelling upon impact. [028] In preference the movable weight is in communication with a ratchet arrangement wherein the relative movement away or towards the spring 25 member by the mass weight is held in its final position by the interaction of the movable weight with the ratchet arrangement upon impact.

5 [029] As the person skilled in the art will appreciate the ratchet arrangement provides a simple mechanical means whereby the deflection of the movable weight from its initial position to its final position can be determined subsequent to a collision. The final position of the movable weight is maintained by the 5 ratchet system. [030] In one form of the invention the spring and mass unit includes a spring arrangement wherein upon impact the movable weight will be deflected such that the windings of the spring will be extended due to tension applied by the attached movable weight whereas in an alternative embodiment the movable 10 weight is in contact with an uncompressed spring and upon impact the movable weight is adapted to compress the windings of the uncompressed spring member. [031] As the person skilled in the art will appreciate by having an understanding of the kinetic energy of the movable weight (I MV 2 where V is 15 the initial speed of the vehicle and M is the mass of the movable weight), and is dissipated by compression in the spring S. The work done on the spring is KX 2 where K is the spring constant of S and X is the amount of spring compression or extension. In the event of sudden stop of the vehicle, the minimum collision speed of the vehicle is proportional to the degree of compression or extension 20 of the spring S by the mass M. The movable weight is locked in position after compression of the spring by the ratchet arrangement as referred to above. [032] In preference the apparatus is housed inside a metal box of which is adapted to be mounted to the underside chassis of the vehicle. [033] An advantage of such an arrangement is that for the first time without the 25 use of any complicated electronic system or measuring devices for sensing impact speed, there is provided a simple vehicle magnitude and multidirectional impact apparatus that can work off simple mechanical features and requires no 6 external electrical charging through the use of a battery or through the vehicle's electronic instrumentation system. [034] Advantageously by placing the spring and mass system upon a frame which can rotate through an arc of 1800 means that if the vehicle slews up to 5 900 to the left or right prior to the collision, the spring and mass unit, which is responsible for measuring the speed of impact will still be maintained in its original direction of travel thus ensuring the apparatus is in correct alignment with the impacted object thereby allowing the spring and mass unit to provide an accurate indication of the speed at which the vehicle was travelling. 10 [035] Advantageously as the movable weight is also included inherently as part of its design a scriber which is in contact with a recording surface means that the apparatus not only determines the magnitude of the impact but also can provide information as to the direction in which the vehicle was travelling upon impact. 15 [036] As the person skilled in the art will appreciate for the most part the device when fitted in a metal box can then be secured to a vehicle and if impact has occurred measurement of degree of compression or extension of the spring member as part of the spring and mass unit would be achieved by removing the device from the vehicle and using a calibrated scale on the measuring device to 20 facilitate collision speed measurements. [037] Checks can be made on the conformity of the values of the mass of M and the spring constant K with accepted production tolerances. Such checks would also be made during the manufacturing process. [038] As is to be expected the impact record apparatus would be robust, 25 tamper-proof and independent of electric batteries or the vehicle electrical system. It would also be impervious to the ingress of water, oil or grease. [039] Now to describe the invention more fully what follows here is preferred embodiments.

7 [040] Figure 1 is a perspective view of the vehicle speed magnitude and multidirectional impact apparatus of the invention. [041] Figures 2A and 2B show the original and deflected position of the movable weight in one preferred embodiment of the invention wherein the 5 spring member starts in an uncompressed configuration. [042] Figures 3A and 3B show schematically initial and deflected positions of the movable weight unit wherein the spring member is in a starting untensioned configuration and is extended out upon impact. [043] Figure 4 is a schematic representation showing a vehicle deviating from 10 the original direction of travel as it slews into impact. [044] Figure 5 is a schematic view showing the scriber with the recording surface. [045] Referring to the drawings now in greater detail where there is provided a vehicle speed magnitude and multidirectional impact recorder apparatus shown 15 generally as 10. [046] The apparatus includes a main frame 12 which is able to rotationally and laterally support a spring and mass unit which in the embodiment of Figure 1 has a spring member 16 communicating with a movable weight 18 and a ratchet mechanism 20. 20 [047] As the person skilled in the art would appreciate the ratchet mechanism could just as appropriately be designed and arranged around the shaft. [048] The movable weight 18 in contact with the spring 16 in the embodiment shown in Figure 1 and also Figures 2A and 2B is initially uncompressed.

8 [049] The movable weight 18 is free to travel along a guide shaft 19 which is coaxial with the spring 16 and movable weight 18. [050] Symmetrical opposite rungs 21 support said ratchet mechanism 20 [051] The rungs 21 are threaded with the ratchet teeth arrangement 20 to act 5 as a linear rack for engagement with the movable weight unit 18. [052] As the person skilled in the art will appreciate as the movable weight 18 is deflected forward upon impact and as shown in Figure 2B, the spring member 16 will have its windings compressed. [053] The change of the movable weight from its original position can then be 10 used to calculate the speed at which the vehicle is travelling at impact as outlined previously above. [054] As the spring and mass unit is pivotally supported 22 for rotatable lateral movement as shown by arrow 23, the spring mass unit is able to rotate so that the spring mass unit maintains its original orientation and direction of travel. 15 [055] Advantageously as a scriber 24 has been included as part of the arrangement the direction of the vehicle upon impact can also be determined by the imprint left by the scriber 24 has made upon the recording surface 26 that is included as part of the apparatus. [056] As the person skilled in the art can appreciate Figures 2A and 2B and 20 Figures 3A and 3B respectively show different embodiments of both the starting and impact positioning of the movable weight which in the case of the Figure 3 shows an uncompressed spring whereas in the scenario shown in Figure 3 the spring starts in its untensioned position. [057] Nonetheless the point remains the same that there is relative movement 25 between the movable weight and the spring member and the movable weight is 9 able to be held in that impact position for recording purposes by virtue of the threads on the guide shaft or other appropriate ratchet type arrangement. [058] Figure 4 simply shows a schematic representation wherein when the impact apparatus of the invention 10 is mounted on a vehicle 36. It can be 5 observed that the spring and mass unit shown generally at 38 maintains its original orientation of direction of travel even though the vehicle 36 starts to slew up to 900 to the left or right prior to the impact of the vehicle 36 with the impacted obstacle 40. [059] Figure 5 shows the scriber 24 contacting with the recording surface 26. 10 [060] Advantageously even though the vehicle 36 has slewed off direction the spring and mass unit remains appropriately aligned so that.upon impact the appropriate deflection of the movable weight with the spring can occur in order to detail accurately the amount of deflection that has taken place.

Claims

1. A vehicle magnitude and multidirectional impact recording apparatus, for the measuring of the speed and direction of a vehicle involved in a collision with a stationary object or another vehicle, said apparatus 5 including; a main frame, said frame adapted to support a spring and mass unit which is able to rotate through an arc of 180 degrees, said spring and mass unit including a movable weight in combination with 10 a spring member, said movable weight adapted for relative movement against or from spring member for a compression or extension of the windings of said spring member when the motion of the vehicle is arrested through impact, 15 such that when the vehicle becomes involved in an impact or collision and said vehicle has slewed off a direct travel impact projection, said spring and mass unit rotates such that the spring and mass unit maintains its original orientation of direction of vehicle travel so that the spring and mass unit is correctly aligned for an accurate indication of 20 vehicle impact speed recordable from the relative extension or compression of the spring member against the original position of the movable weight.

2. The vehicle magnitude and multidirectional impact recording apparatus of claim 1 further including a scriber which is connected to the movable 25 weight.

3. The vehicle magnitude and multidirectional impact recording apparatus of claim 2 wherein scriber is adapted to mark out upon a recording surface in contact with the scriber as part of the impact apparatus, such that as the vehicle slews off direct forward vehicle travel direction, the 5 relative markings of the scriber on the recording surface can identify the direction in which the vehicle was travelling upon impact.

4. The vehicle magnitude and multidirectional impact recording apparatus of claim 3 wherein the movable weight is in communication with a ratchet arrangement wherein the relative movement away or towards the spring 10 member by the mass weight is held in its final position by the interaction of the movable weight with the ratchet arrangement upon impact.

5. The vehicle magnitude and multidirectional impact recording apparatus of claim 4 whereby the deflection of the movable weight from its initial position to its final position is determinable subsequent to a collision so 15 that the final position of the movable weight is maintained by the ratchet system.

6. The vehicle magnitude and multidirectional impact recording apparatus of claim 1 wherein the spring and mass unit includes a spring arrangement wherein upon impact the movable weight will be deflected 20 such that the windings of the spring will be extended due to tension applied by the attached movable weight.

7. The vehicle magnitude and multidirectional impact recording apparatus of claim wherein the movable weight is in contact with an uncompressed spring and upon impact the movable weight is adapted to compress the 25 windings of the uncompressed spring member.

8. The vehicle magnitude and multidirectional impact recording apparatus of any one of claims 1 to 7 wherein the apparatus is housed inside a 12 metal box of which is adapted to be mounted to the underside chassis of the vehicle.

9. A vehicle magnitude and multidirectional impact recording apparatus as 5 described in the preferred embodiment included with this specification.