Claims:We claim:

1. A body structure for a small vehicle to reduce dash panel and steering intrusions into the safety cage of the vehicle, wherein the body structure comprises:

- at least one pair of lower crush cane and a bumper beam to prevent penetration;

- at least one pair of upper crush cane and shotgun members each for facilitating the crush energy absorption in the upper part of the vehicle;

- at least one X cross-member for controlling the intrusions of the dash panel and steering into the safety cage of the vehicle; and

- at least one top cross-member; at least one pair of head lamp brackets; at least one pair of head lamp support brackets, and at least one upper crash can support.

2. Body structure as claimed in claim 1, wherein the lower crush cane is configured as main part to absorb the crash energy of the impact and to transfer the absorbed crash energy to the longitudinal side members of the vehicle body structure.

3. Body structure as claimed in claim 1, wherein the upper crush cane is welded to the top cross-member and bolted to the shotgun member to absorb some of the energy coming from the colliding body and to transfer the load to the shotgun members.

4. Body structure as claimed in claim 1, wherein the shot gun members are connected to the hinge pillars (A-pillars) by spot welding for transferring the load coming from the upper crash can to the hinge pillars.

5. Body structure as claimed in claim 1, wherein the X cross-member is connected to the dash panel for controlling intrusions of the dash panel and steering into the safety cage of the vehicle.

6. Body structure as claimed in claim 1, wherein the lower crush cane is positioned in front of the tires and extends from the wheel house upper members, and connected to the longitudinal side-members to transfer the frontal impact load to the pair of longerons mounted on the vehicle sub-frame, thereby preventing the penetration of the hinge pillars of the vehicle even in offset collisions.

7. Body structure as claimed in claim 5, wherein the dash panel intrusion is reduced to within a range of 140 to 180 mm, particularly, about 160 mm at a crash speed of about 56 kmph for a small car with the kerb-weight in a range of 700 to 900 kg.

8. Body structure as claimed in claim 1, wherein the frontal impact load transfer paths are as under:

- Longerons to vehicle sub-frame;

- Longerons to the hinge-pillars;

- Longerons to the rockers and

- Longerons to the tunnel.

9. Body structure for a small vehicle to reduce dash panel and steering intrusions into the safety cage of the vehicle, wherein the body structure comprises:

- lower crush canes positioned in front of the tires and extends from the wheel house upper members, and connected to the longitudinal side-members to transfer the frontal impact load to the pair of longerons mounted on the vehicle sub-frame;

- a bumper beam;
- upper crush canes welded to the top cross-member and bolted to the shotgun member;

- shotgun members connected to the hinge pillars (A-pillars) by spot welding for transferring the load coming from the upper crash can to the hinge pillars by absorbing crush energy in the upper part of the vehicle;

- a X cross-member connected to the dash panel for controlling the intrusions of the dash panel and steering into the safety cage of the vehicle;

- a top cross-member;

- head lamp brackets;

- head lamp support brackets, and

- upper crash can support;

wherein the frontal impact load is transferred via longerons to vehicle sub-frame, hinge-pillars, rockers and tunnel to reduce the intrusions of the dash panel and steering into the safety cage of the vehicle in a range of 140 mm to 180 mm, particularly about 160 mm.

10. Body structure as claimed in anyone of the claims 1 to 9, wherein frontal crush zone absorbs maximum energy of impact, the middle transition zone absorbs minimum energy of impact along with a controlled deformation of the components/sub-assemblies disposed therein and no crash energy reaches the safety zone or passenger cabin/boot space of the vehicle, and which undergoes no deformation.

Dated: this day of 14th September, 2015. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT , Description:FIELD OF INVENTION

The present invention relates to the body structures for passenger safety in automobiles, particularly to the body structures provided in automobiles in case of a frontal impact with an obstacle, and more particularly to the body structures for absorbing the impact energy in a frontal collision with an obstacle for the preservation of the passenger compartment in a small vehicle.

BACKGROUND OF THE INVENTION

With the advent of automobiles, it was a common practice to make them of extremely rigid body structures, for safeguarding the occupants in a vehicle in case of collision with obstacles. Such body structures were very resistant to deformation and therefore, all the impact or collision forces were transferred to the occupants of the automobiles, leading to serious and even fatal damages to them. To make automobiles safer for the occupants with respect to the erstwhile automobile body structures, the concept of providing “Crumple Zones” was developed sometime in early 1950’s.

Normally, crumple zone is a place at the front and rear of an automobile, whereby first the impact energy developed during an impact is absorbed by the deformation of predetermined parts of the vehicle whilst strengthening the passenger cabin by using high strength steel and more beams, then delaying a collision by disallowing the two rigid bodies to instantaneously collide with each other, i.e. increasing the time before the vehicle comes to a final halt. There was misconception about the construction of a crumple zone that weakening of the front portion of the vehicle would cause the occupants in the cabin to become crushed. However, this was found to be incorrect, because the location of the crumple zones are in the front and back of the vehicle cabin and during a collision, the crumple is formed in the space of the engine compartment or the boot compartment. There is also a worry that production and use of the small vehicle, which are substantially cheaper to run and maintain; much smaller crumple zones are available in them due to their smaller size compared to larger or mid-sized vehicle.

The designing of a crumple zone is to absorb and redirect impact forces. If the entire car is designed as a crumple zone, theoretically the passengers would be crumpled with the car. Therefore, it is common practice to build the passenger cabin to resist penetration from outside object, such as the engine. This is achieved by building the passenger cabin with a rigid, strong framework to avoid distortion and the occupants from being thrown out. The survival in a crash depends on controlling the energy in motion or the kinetic energy of the vehicle, body structure and the passengers. Either, the vehicle design will disperse the impact energy and safeguard the occupants or if the occupants absorb the impact energy, they are prone to sustain fatal injuries or even die in extreme cases. The frontal impact constitutes almost 40% of all crash accidents with automobiles.

With the prospect of increasing exports of automobiles from India as a global manufacturing hub, it is necessary to design automobiles complying with major foreign-based regulatory agencies, e.g. those based in Europe and USA. One of the important test regulations in Europe is formulated under the European New Car Assessment Programme (Euro NCAP). Under this programme, a frontal impact should have 40% overlap offset before colliding with a deformable barrier (ODB), when a vehicle is travelling at a speed of 64 kmph (Fig. 2). In fact, this is substantially higher vehicle test speed than defined under the European Legislations, i.e. a minimum speed to be 56 kmph.

DISADVANTAGES WITH THE PRIOR ART

The main challenges for an effective vehicle compartment design for small cars are: (a) how to reduce intrusion of dash panel into the vehicle compartment, which directly controls the survival space for the occupants, and (b) how to reduce steering wheel displacement, which in turn controls the secondary impact between the occupants and restraint parts. These challenges are accentuated by the limited space available in small cars. In the existing designs of the passenger compartment in small cars, during a frontal crash, the passenger compartment intrudes between the offset deformable barrier and small car.

DESCRIPTION OF THE PRESENT INVENTION

For preserving the passenger compartment space during a frontal impact is extremely significant for the self-protection of small cars. It is well known that the criteria such as - crash speed, mass, stiffness and geometric interaction have a considerably influence on the intrusion of the passenger compartment in any such frontal impact.

Accordingly, a body structure for a small car in an offset deformable barrier impact is proposed in accordance with the present invention. This improved small car body structure has been successfully tested in a crash between the offset deformable barrier and small cars at a crash speed of 56 kmph for a small car having the kerb weight of about 750 kg. This innovative body structure for the front end of small cars has achieved the desired efficiency of energy absorption as per regulatory criteria and proved well to maintain the cabin integrity of the small car. This innovative configuration of the body structure includes new shotgun, crush cane and X cross member concept in order to reduce the dash panel intrusion into the vehicle compartment, directly controlling the survival space for the small car occupants. This body structure also reduces the steering wheel displacement for controlling the secondary impact between the occupants and restraint parts. The novel shotgun is connected to the hinge pillar and the new crush cane is connected to the long member. Furthermore, the X cross member is connected to dash panel.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide a small car body structure with a sufficient crumple zone.

Another object of the present invention is to provide a small car body structure capable of efficiently absorbing the impact energy during a frontal collision.

Still another object of the present invention is to provide a small car body structure for reducing the intrusion of dash panel into the passenger cabin.

Yet another object of the present invention is to provide a small car body structure for reducing the steering wheel displacement.

A further object of the present invention is to provide a small car body structure capable of maintaining the passenger cabin integrity.

A still further object of the present invention is to provide a small car body structure

These and other objects and advantages of the present invention will become more apparent from the following description when read with the accompanying figures of drawing, which are, however, not intended to limit the scope of the present invention in any way.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a body structure for a small vehicle to reduce dash panel and steering intrusions into the safety cage of the vehicle, wherein the body structure comprises:

- at least one pair of lower crush cane and a bumper beam to prevent penetration;

- at least one pair of upper crush cane and shotgun members each for facilitating the crush energy absorption in the upper part of the vehicle;

- at least one X cross-member for controlling the intrusions of the dash panel and steering into the safety cage of the vehicle; and

- at least one top cross-member; at least one pair of head lamp brackets; at least one pair of head lamp support brackets, and at least one upper crash can support.

Typically, the lower crush cane is configured as main part to absorb the crash energy of the impact and to transfer the absorbed crash energy to the longitudinal side members of the vehicle body structure.

Typically, the upper crush cane is welded to the top cross-member and bolted to the shotgun member to absorb some of the energy coming from the colliding body and to transfer the load to the shotgun members.

Typically, the shot gun members are connected to the hinge pillars (A-pillars) by spot welding for transferring the load coming from the upper crash can to the hinge pillars.

Typically, the X cross-member is connected to the dash panel for controlling intrusions of the dash panel and steering into the safety cage of the vehicle.

Typically, the lower crush cane is positioned in front of the tires and extends from the wheel house upper members, and connected to the longitudinal side-members to transfer the frontal impact load to the pair of longerons mounted on the vehicle sub-frame, thereby preventing the penetration of the hinge pillars of the vehicle even in offset collisions.

Typically, the dash panel intrusion is reduced to within a range of 140 to 180 mm, particularly, about 160 mm at a crash speed of about 56 kmph for a small car with the kerb-weight in a range of 700 to 900 kg.

Typically, the frontal impact load transfer paths are as under:

- Longerons to vehicle sub-frame;

- Longerons to the hinge-pillars;

- Longerons to the rockers and

- Longerons to the tunnel.

A body structure for a small vehicle to reduce dash panel and steering intrusions into the safety cage of the vehicle; the body structure comprises:

- lower crush canes positioned in front of the tires and extends from the wheel house upper members, and connected to the longitudinal side-members to transfer the frontal impact load to the pair of longerons mounted on the vehicle sub-frame;

- a bumper beam;

- upper crush canes welded to the top cross-member and bolted to the shotgun member;

- shotgun members connected to the hinge pillars (A-pillars) by spot welding for transferring the load coming from the upper crash can to the hinge pillars by absorbing crush energy in the upper part of the vehicle;

- a X cross-member connected to the dash panel for controlling the intrusions of the dash panel and steering into the safety cage of the vehicle;

- a top cross-member;

- head lamp brackets;

- head lamp support brackets; and

- upper crash can support;

wherein the frontal impact load is transferred via longerons to vehicle sub-frame, hinge-pillars, rockers and tunnel to reduce the intrusions of the dash panel and steering into the safety cage of the vehicle in a range of 140 mm to 180 mm, particularly about 160 mm.

Typically, frontal crush zone absorbs maximum energy of impact, the middle transition zone absorbs minimum energy of impact along with a controlled deformation of the components/sub-assemblies disposed therein and no crash energy reaches the safety zone or passenger cabin/boot space of the vehicle, and which undergoes no deformation.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings, which include:

Figure 1 shows a schematic diagram of an automobile indicating different portions covered under crash regulations, e.g. in Europe and the USA,

Figure 2 shows the test condition for conducting a crash test, i.e. before impacting the Offset Deformable Barrier (ODB) prescribed according to Euro NCAP for an automobile,

Figure 3 shows the physics of crush after of ODB crash test shown in Fig. 2,

Figure 4a shows the bottom view of the deformation of a baseline design of the front portion of an automobile after conducting ODB crash test of Figure 2,

Figure 4b shows the bottom view of the deformation of the improved design of the front portion of a small car in accordance with the invention, after conducting the ODB crash test shown in Figure 2,

Figures 5a to 5d show the structural deformation in a crash of an automobile,

Figure 6 shows the top view of an automobile shown in Figure 3 for crush space measurement indicating the crushable components,

Figure 7 schematically shows the load distribution philosophy for an automobile after an impact against an obstacle, such as an ODB,

Figures 8a and 8b show the respective perspective front view from one front crashed end of the baseline design and the improved body structure for an automobile configured according to the present invention,

Figure 9a shows the respective perspective view of the baseline design for an automobile, e.g. a small car,

Figure 9b shows the respective perspective view of the body structure assembly for a small car configured according to the present invention,

Figure 10 an exploded view of the body structure assembly according to the present invention as shown in Figure 9b,

Figure 11 shows graphical representation for comparing the vehicle pulse of baseline design (Fig. 9a) and the body structure assembly (Fig. 9b),

Figure 12 shows graphical representation for dash panel intrusion for baseline design,

Figure 13 shows graphical representation for dash panel intrusion for the improved body structure assembly (Fig. 9b), and

Figure 14 shows the load paths in the crush zone of an automobile on an impact against an obstacle, e.g. an ODB.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, different embodiments of the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.

Figure 1 shows a schematic diagram of an automobile for different portions covered under various crash regulations, e.g. in Europe and the USA. These regulations concerns crash test of the portions against front impact (IF), side impact (IS), rear impact (IR), pedestrian protection (PP), Instrument panel (IP), steering wheel (S), side windows (SW), roof (Rf), headrests (Hdr), seats (St), seat belts (Sb) and bumper (B) crash. The figure also shows the possible roll over of the automobile by an arrow (Ro).

Figure 2 shows the test condition for conducting a crash test, i.e. before impacting the offset deformable barrier (ODB) prescribed according to Euro NCAP for an automobile, e.g. a small car here. ODB comprises a fixed rigid barrier 110 and a deformable face, which in turn consists of main honeycomb block 112 and a bumper element honeycomb 114, both made of aluminum. The body structure improved in accordance with the present invention is configured to reduce passenger compartment intrusion in a crash between offset deformable barrier and the small car (Figure 3). 40% overlap criteria should be fulfilled for a frontal impact according to the Euro NCAP. This means that before impacting the deformable barrier (ODB) at a speed of 64 kmph under this test, a 40% overlap of the width (W) of the widest part of the automobile, excluding the wing mirrors, should be offset with the ODB. The requirement under Euro NCAP is more stringent than the minimum safety standards (56 kmph) prescribed under the European regulations. Thus, a test crash speed of 56 kmph is used for the small car having a kerb weight of about 750 kg in order to test the improved body structure of the present invention for compliance with these European minimum standards for frontal impact. The proposed innovative body structure for the front end of small cars achieved efficiency of energy absorption and was able to maintain cabin integrity.

Figure 3 shows the physics of crush after of ODB crash test for a vehicle 120 against an ODB 110 shown in Figure 2. When the vehicle 120 having a kerb weight (m) and travelling at a velocity (v) goes or is made to undergo a frontal impact against an obstacle (ODB 110 here), the kinetic energy of the vehicle 100 is calculated as under:

K. E. = ½ m.v2

On frontal impact, the work done is:

W. D. = F.D

wherein, F is the average force on vehicle by the ODB 110 and D is the crush plus rebound of the vehicle 120.

The ideal body structure of the vehicle 120 should be capable of dissipating this kinetic energy into vehicle deformation (as Work Done), however, this should be done away from the vehicle occupants. This is required to maximize the crush space inside the vehicle 120 and also to minimize the intrusion of the dash panel and steering wheel 112 into the vehicle compartment 114. Here, it is assumed that ODB 110 applies a constant axial force on the vehicle 120 during the frontal crash test. The energy dissipation rate would also be proportional to the injuries sustained in any such frontal impact.

Figure 4a shows the bottom view of the deformation of a baseline design of the front portion of an automobile after conducting the ODB crash test shown in Figure 2. A crash barrier is provided for crash test during frontal impact of a vehicle 20.The barrier preferably consists of a fixed rigid barrier 10 supporting the main honeycomb block 12, which in turn support the bumper element honeycomb 14. A typical crumple region 16 is shown due to permanent deformation after the offset frontal impact of the baseline design.

Figure 4b shows the bottom view of the deformation of the improved design of the front portion of a small car in accordance with the invention, after conducting the ODB crash test shown in Figure 2. The crash barrier is provided for crash test during frontal impact of a vehicle 120. Here also, the barrier consists of a fixed rigid barrier 110 supporting the main honeycomb block 112, which supports the bumper element honeycomb 114. A crumpled region 116 is also shown due to permanent deformation after the offset frontal impact of the body structure in accordance with the present invention. This design offers a substantially reduced crumpled region 116 with respect to the baseline design 16 of the state of the art (Fig. 4a).

Figure 5a to 5b show the structural deformation in a crash of an automobile. At stage (a), no vehicle deformation has yet set-in as the vehicle has just hit the crash barrier or an obstacle; at stage (b), the bending has started in the vehicle body structure; and at stage (c), the vehicle has deformed to absorb the kinetic energy of the crash in the designed crumple zone. A graphical representation of the structural deformation during this crash is shown in graph (d), in which force of impact is plotted on ‘Y’ axis and deflection on the ‘X’ axis.

Figure 6 shows the side view of an automobile shown in Figure 3 for crush space measurement indicating the crushable components. The crush has two components, i.e. static crush and a dynamic crush. The static crush includes free crush and the crushed components, whereas dynamic crush includes static crush plus dynamic crush intrusion. Free crush 130 is shown in grey colour, crushable components 140 in green colour and toe-pan intrusion 140 in blue colour. The distance between the ball of foot 150 and the front-most part 160 of the vehicle 120 is the front end length L1 of the vehicle 120.

Figure 7 schematically shows the load distribution for an automobile after an impact, e.g. against an ODB during a crush test. The crush zone includes the components/sub-assemblies disposed at the front –most portion of the vehicle, which are designed to absorb maximum impact energy. The transition zone includes the components/sub-assemblies disposed under the bonnet, e.g. engine etc. and are designed to absorb minimum impact energy and for a controller deformation. The safety cage predominantly includes the passenger cabin and boot/luggage space, which is ideally designed to have no deformation at all. The transition zone bridges the offset between the load paths in the crush zone and the safety cage and thereby enables effective load transfer to provide stability control.

Figure 8a and 8b show the respective perspective front view from one front crashed end of the baseline design and the improved body structure for an automobile configured according to the present invention. It is clear from the figure that the body structure (Fig. 8b) in accordance with the present invention facilitates a substantially reduced crushed zone in comparison to the base line design (Fig. 8a) of the state of the art.

Figure 9a shows the respective perspective view of the baseline design (Fig. 9a) for an automobile. This head lamp supporting bracket is directly connected to dash panel, which causes high dash panel and steering column intrusion.

Figure 9b shows the respective perspective view of the baseline design (Fig. 9a) and the improved body structure assembly (Fig. 9b) for an automobile configured according to the present invention. To reduce the dash panel and steering column intrusion, a new load path is configured, which facilitates the transfer of some of the impact loads to the hinge pillar by the top crush cane and top cross member. In addition, an X cross member is placed for reducing the intrusion further.

Figure 10 an exploded view of the improved body structure assembly shown in Figure 9b. The proposed structure consists of three components; a lower crush cane 210 and bumper beam 220 to prevent penetration; an upper crush cane 230 and shotgun member 240 to assist energy absorption in the upper part of the vehicle; and a X cross member 250 to control dash panel and steering intrusions. The new ‘lower crush cane 210’ is positioned in front of the tires and extends from the wheel house upper member, and connected to the side long members. This prevents the penetration of the hinge pillar of the respective vehicles in offset collisions. On impact, the lower member makes contact with the front structure of the other vehicle and deforms, thus achieving a high level of energy absorption. Accordingly, the body structure assembly in accordance with the present invention a lower crush cane 210 as the main part of the innovative body structure to function of absorbing the crash energy and to transfer this absorbed crash energy to the long member of the body structure. The upper crush cane 230 is welded to the top cross member 250 and bolted to the shotgun member 240 with the function of absorbing some of the energy coming from the barrier and transfer the load to the shotgun member 240. The shot gun member 240 is connected to the hinge pillar (A-pillar) by spot welding and has the main function of transferring the load coming from the upper crash can 230. The X cross member 250 is connected to the dash panel 260 to control the intrusions of the dash panel and steering. This body structure also includes a head lamp bracket 215, a head lamp support bracket 235, an upper crash can support 225 and a top cross-member 255.

Figure 11 shows graphical representation for comparing the vehicle pulse of baseline design (Fig. 9a) and the improved body structure assembly (Fig. 9b). The graph is plotted with dynamic crush on X axis and acceleration on the Y axis. It is clear from this graph that the baseline design (in red colour) is softer than the improved body structure (in green colour).

Figure 12 shows graphical representation for dash panel intrusion plot for baseline design (Fig. 9a). The graph shows the time in measured (in seconds) on the X axis versus the resultant displacement (in mm) plotted on Y axis. Here, the intrusion observed is 450 mm.

Figure 13 shows graphical representation for dash panel intrusion for the improved body structure assembly (Fig. 9b). The graph again shows the time in measured (in seconds) on the X axis versus the resultant displacement (in mm) plotted on Y axis. Here, the intrusion observed has substantially reduced from 150 mm in baseline design to just 160 mm in the inventive design.

Figure 14 shows the load paths in the crush zone of a small car on impacting against an ODB under crush test. On impact against an ODB, the front load input FLI is transferred to the pair of longerons LG, which transmit the received energy of impact to the sub-frames SF, tunnel Tn and the superstructure of the vehicle, e.g. A-pillars A-P and Rockers Rc. By the time the impact energy reaches the

Working of the Invention:

Frontal crashes are responsible for more deaths and serious injuries than any other accident type. A typical scenario is a head-on collision between two oncoming cars at moderately high speeds. In most collisions of this type, only a part of the vehicle front width structure is involved, i.e. the two colliding vehicles are offset. In the full-scale test, the car is driven at 56km/h and with 40 percent overlap into a deformable barrier which represents the oncoming vehicle. The test replicates a crash between two cars of the same weight, both travelling at a speed of 56km/h. Two frontal impact dummies representing the average male are seated in the front. In this crash, the vehicle structure is put to the test. Limited structural engagement may expose occupants to increased intrusions. Crash forces have to be efficiently directed to parts of the car where the energy can be efficiently and safely absorbed. The front crumple zone must collapse in a controlled way, leaving the passenger compartment as less deformed as possible. Rearward movement of the steering wheel and the pedals must be limited if serious injuries are to be avoided.

Technical advantages and economic significance

The improved body structure in accordance with the present invention for a small car in an offset deformable barrier impact has the following advantages:

• With minimal front crumple zone (200mm) we able meet the regulation targets.

• Passenger compartment is stable

• Occupant injuries are well below the regulation targets.

• A universal benefit would accrue from a general crashworthiness design improvement.

• Fewer ankle-foot injuries from structural improvement to the floor and toe-pan areas.

• A reduction in neck injuries by including a neck injury criterion.

• Equal effectiveness would apply to occupants in all front-seating positions.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to implies including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.

The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention.

Although, only the preferred embodiments have been described herein, the skilled person in the art would readily recognize to apply these embodiments with any modification possible within the spirit and scope of the present invention as described in this specification. Therefore, innumerable changes, variations, modifications, alterations may be made and/or integrations in terms of materials and method used may be devised to configure, manufacture and assemble various constituents, components, subassemblies and assemblies according to their size, shapes, orientations and interrelationships.

The description provided herein is purely by way of example and illustration. The various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention. The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.

While considerable emphasis has been placed on the specific features of the preferred embodiment described here, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other changes in the preferred embodiment of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.