DESC:TECHNICAL FIELD
[0001] The present subject matter relates to a motor vehicle. More particularly, the present subject matter relates to the energy storage device.
BACKGROUND
[0002] In many countries of the world, a three wheeled motor vehicle is a significant mode of public transportation. It is vastly used as a point to point mode of transport in rural and urban areas also referred to as autorickshaw. Generally, the motor vehicle has a driver compartment in a front portion and a passenger load compartment in a rear portion. In case of a passenger vehicle, the rear compartment comprises of a passenger seat. In the posterior portion of the rear compartment a power unit is provided, which powers the vehicle. A driver operates the vehicle from the front compartment. A driver seat is provided in the front compartment so that the driver operates the vehicle in a sitting position. The suspension structure for three wheeled vehicle normally employs separate trailing arm with rear suspension system to support the body on the two rear wheel assemblies. Also, a storage compartment provided behind a rear seat of the vehicle provides space for storage of goods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The detailed description is described with reference to a passenger transport layout of a three wheeled vehicle along with the accompanying figures. The same numbers are used throughout the drawings to reference like features and components.
[0004] Fig.1 is a side view of a motor vehicle as per one embodiment of the present invention.
[0005] Fig. 1a is a rear view of a motor vehicle as per one embodiment of the present invention.
[0006] Fig.2 shows a frame structure of motor vehicle, as per one embodiment of the present invention
[0007] Fig.3 is partial perspective view of a motor vehicle having driver seat assembly in open condition as per one embodiment of the present invention.
[0008] Fig. 3a is a bottom side view of a driver seat assembly, as per one embodiment of the present invention
[0009] Fig. 4 is a partial perspective view of a vehicle with housing assembly of one or more stack of energy storage device
[00010] Fig 4a is a perspective view of the housing assembly, as per one embodiment of the present invention.
DETAILED DESCRIPTION
[00011] The arena of technology pertaining to transportation has undergone a tremendous transformation over the years, such that the present concentration is focused upon the efficiency and cost of manufacturing, which includes the cost of materials, assembly cost, cost of inventory handling etc. Simultaneously, there has also been need in the industry to provide stronger, lighter and economically advantageous vehicles that consume less power. Electric power storage device driven vehicles happen to be eco- friendly, in line with the Go Green initiative of various organizations. These Vehicles may be two, three or four wheelers depending upon the requirement of the consumer and have multiple applications.
[00012] In automobile vehicle industry, electric vehicles are introduced to control air pollution caused due to IC engine powered vehicles. Currently, the electric vehicles are classified into two groups, namely pure electric and extended electric vehicles (also known as hybrid vehicles). The hybrid vehicles have a primary electric drive with associated energy storage device and an internal combustion engine coupled to an electric motor/generator.
[00013] In recent years, hybrid vehicles and electric vehicles have become quite popular due to high oil prices and the environmental impact of pure fuel consumption vehicles. In particular, the hybrid vehicle has become an intermediate choice for those consumers wishing to reduce fuel consumption while at the same time increase their allowable travel distance. In most developing & under-developed markets, a low-cost three-wheeler is often employed as a popular public mode of transport or a goods carrier vehicle. In case of a passenger transport layout, the vehicle rear portion is configured with a passenger seating compartment while in case of a goods carrier, the rear portion has a loading trailer platform layout to carry goods. Unlike conventional four wheeled vehicles, the three-wheeled vehicle is compact, highly weight efficient & economical mode of transport. Typically, such multi-track vehicles have a steering axis disposed centrally along the longitudinal mid-plane of the vehicle with the rider seated co-axially along the same mid-plane. Such vehicles are commonly powered by IC engines & electrification of such public transport vehicles has been of much interest to bring down emissions. Any major alteration or modification on a vehicle to adapt to different powertrains for given product is undesirable owing to adverse impact on manufacturing complexity, variety, logistics, supply chain challenges as well as cost. Often a manufacturer prefers to have a platform product solution wherein a basic structure of the vehicle can be common across the types of powertrains used. This enables great flexibility for the manufacturer to operate with a standardised platform of product across various markets, variants etc. with different powertrains e.g. IC engine or Hybrid etc. depending on the requirements.
[00014] The hybrid vehicles have distinct advantage of allowing longer travel, since at least one power source is always available to drive the vehicle. Hence, there is reduced risk of running out of fuel which can potentially occur with a traditional internal combustion powered vehicle. The hybrid vehicle can operate as an IC engine vehicle or as an electric vehicle or even as both. For example, driving on terrain or for long distances, IC engine can be used and for shorter distances electric propulsion system can be used..
[00015] The electric vehicles using electric motors as a driving source and hybrid vehicles combining other driving sources such as an electric motor and an engine have been put to practical use. The above-mentioned automobile is equipped with an energy storage device for supplying electric power as electric energy to an electric motor. In this particular type of vehicles, the vehicle's driving force is provided from an energy storage device in order to receive the energy required for driving the vehicle. The energy storage device employed, for example, is a battery that can be repeatedly charged and discharged, such as a nickel-cadmium battery, a nickel-hydrogen battery, and a lithium-ion battery. The energy storage device is housed in a case and is installed in the vehicle.
[00016] Accordingly in order for the energy storage device to supply sufficient energy to the motor, a large-capacity energy storage device should be provided. However, due to a spatial limitation in such compact three-wheeled vehicles, mounting a large-capacity energy storage device is a challenge.
[00017] Therefore, as per known art, a light weighted stack of energy storage device is typically developed while maintaining the efficiency of the energy storage device and is placed where the user’s comfort is not compromised. The stack of energy storage device is disposed on a trolley, where the trolley is placed on a frame structure of the vehicle. The stack of energy storage device is covered by a protective shield and a seat of the vehicle. Further, the protective shield is attached with the seat and the frame structure with attachment means like fasteners. The stack of energy storage device is locked with a locking mechanism having separate lock and key. The arrangement of the stack of energy storage device in such configuration which ensures theft proof location of the stack of energy storage device. However, in the configuration as disclosed above, to access any faulty energy storage device from the stack of the energy storage device, the user has to unfasten the fasteners through a tool. However, this leads to problems like accessibility issue, increase assembly and disassembly time etc., while dismantling or swapping the faulty energy storage device from the stack of the energy storage device. Also, keeping traffic conditions in view, it is not advisable to access the faulty energy storage device either from left side or right side of the vehicle. Hence, considering the need to have flexible platform product architecture, the energy storage device needs to be easily accessible for replacement or swapping etc. while at same time maintaining theft proof or tamper proof configuration of the stack of energy storage device in the vehicle.
[00018] Taking example of the motor vehicle pre equipped with CNG cylinder kit, the CNG cylinder kit is placed under the rider or passenger seat of the motor vehicle. The inlet of the cylinder kit is protected by the plastic cover, which is basically a side cover. The plastic cover present in the motor vehicle does not intend to protect the complete CNG cylinder kit as the CNG cylinder is irreplaceable unlike the stack of energy storage device.
[00019] In view of the same, many possible solutions have been disclosed in known art. In known art, a hingedly openable driver seat (referred here as ‘seat’) is locked with a protective shield of the stack of energy storage unit, ensuring theft proof configuration. At the time of accessing the faulty energy storage device from the stack of energy storage device, the seat opens hingedly and rests on a handlebar assembly of the vehicle. However, this configuration has its own disadvantage that while accessing the stack of energy storage device from top, hand of the user interferes with the seat in open condition. This raises safety concern for the user.
[00020] In another known art, a protective shield is disclosed to accommodate a stack of energy storage device. The protective shield includes three members, which ensure ease of accessibility of the stack of energy storage device. However, this configuration may gradually lead to warpage , thus ultimately leading to fit and flush issue.
[00021] Hence, there exists a challenge of disposing one or more stack of energy storage device in motor vehicles, ensuring ease of accessibility while ensuring a theft proof or tamper proof stack of energy storage device in motor vehicles without any major change in design and manufacturing set-up of a stock vehicle.
[00022] Therefore, there is a need to have an improved mounting of the stack of energy storage device which is easy to access or service while ensuring theft proof or tamper proof configuration and also, overcoming all of the above problems and other problems of known art.
[00023] The present invention provides a solution to the above problems while meeting the requirements of minimum modifications in a stock vehicle, at low cost with ease of accessibility etc.
[00024] With the above objectives in view, the present invention relates to the motor vehicle and more particularly to the improved mounting of the stack of energy storage device which is easy to access or service while ensuring theft proof or tamper proof configuration.
[00025] As per one aspect of the present invention, a motor vehicle is provided with a frame structure. The frame structure of the motor vehicle includes a head tube, a main tube and a central tube. A driver seat assembly includes a drive seat, a driver seat frame assembly, a driver seat reinforcing assembly, where the driver seat frame assembly is housed and attached with various attachment means, for example fasteners, on the top of the central tube and a pair of LH (left hand) side tube and RH (right hand) side tube. The driver seat reinforcing assembly is attached with the driver seat with various attachment means, for example, fasteners. The driver seat is attached on the driver seat frame assembly through the driver seat reinforcing assembly. A protective shield is housed under the driver seat for securely protecting a power storage device housing area where a stack of energy storage device is placed.
[00026] As per one aspect of the present invention, the driver seat reinforcing assembly includes a lateral member attached with driver seat, a pair of longitudinal members extending rearwardly from the lateral member. The pair of longitudinal members is fixedly attached with the lateral member of the driver seat frame assembly with various means, for example, a pair of C shaped brackets. The drive seat assembly includes multiple clamping members which clamps the driver seat with the driver seat reinforcing member with various means, for example, fasteners. This configuration ensures stable mounting of the driver seat assembly and enables opening of the driver seat by forming acute angle with respect to driver seat frame assembly of the vehicle, thus acheiving ease of accessibility of the stack of energy storage device which is accommodated under the driver seat. This configuration also ensures theft proof accommodation of the stack of energy storage device under the driver seat.
[00027] As per one aspect of the present invention, one or more stack of the energy storage device is housed in the housing assembly and covered by the protective shield in the vehicle. The housing assembly includes multiple base members, two pairs of upwardly extending members, plurality of guide members and two pairs of vertically upwardly extending members. The multiple base members attaches the housing assembly to the frame structure of the vehicle with various means, for example, fasteners. The frame structure of the vehicle absorbs weight of the one or more stack of energy storage device. The two pairs of upwardly extending members are V shaped, when viewed from side of the vehicle and are disposed at extreme end of the housing assembly. The two pairs of upwardly extending members acts as a supporting member/locating member for the one or more stack of energy storage device while accommodating into the housing assembly. The plurality of guide members are U shaped, when viewed from top of the vehicle and are disposed between the one or more stack of energy storage device, ensuring cooling of the stack of energy storage device through atmospheric air. The two pairs of vertically upwardly extending members are disposed between the plurality of guide members and the two pairs of upwardly extending members. The two pairs of vertically upwardly extending members includes two pairs of holding brackets. The two pairs of holding brackets includes a pair of locking mechanisms extending inclinedly upwardly and then laterally from the two pairs of holding brackets, thereby ensuring locking and ease of assembly of the one or more stack of energy storage device in the housing assembly. This configuration also provides stable housing of the one or more stack of energy storage device in the housing assembly while eliminating requirement of additional attachment means.
[00028] In the ensuing exemplary aspects, the vehicle is a hybrid vehicle. However, it is contemplated that the concepts of the present invention may be applied to any electric vehicle without defeating the spirit of the invention.
[00029] Further "front" and "rear", and "left" and "right" referred to in the ensuing description of the illustrated embodiment refer to front and rear, and left and right directions as seen in a state of being seated on a seat of the vehicle and looking forward. Furthermore, a longitudinal axis refers to a front to rear axis relative to the vehicle, while a lateral axis refers generally to a side to side, or left to right axis relative to the vehicle.
[00030] The present invention is now described briefly in connection with the rendered drawings. It should be noted that like elements are denoted by the same reference numerals throughout the description.
[00031] Fig. 1 & Fig 1a is a side & rear view of a motor vehicle (100) and Fig. 2 is a partial rear perspective view of a frame structure of the motor vehicle in accordance with an embodiment of the present subject matter. For brevity, Fig 1, Fig 1a and Fig 2 shall be discussed together. As per one embodiment, the frame structure (200) of the motor vehicle includes three compartments. A front compartment including a head tube (201) that mounts a handle bar assembly (106) of the motor vehicle and the head tube (201) is capable of steering a front wheel (101), a main tube (206) that connects the head tube (201) and a central frame member (203), a driver seat assembly (104) that is housed on top of the central frame member (203) and a pair of LH side member (205) and a RH side member (202). The motor vehicle also includes a pair of rear wheels (102) and a front fender (103) disposed above the front wheel (101). One or more stack of energy storage device (301) shown in Fig 3 is housed in power storage device housing area (110) under the driver seat assembly (104). As per one embodiment, the frame structure (200) further includes a middle compartment that includes a passenger seat assembly (108) comprising of a seat base bottom (not shown) and a back rest (not shown), a passenger barrier (107) restricting entry/exit of the passengers into the motor vehicle in one lateral direction, a cross frame member (204) capable of mounting a driver back rest (105). Further, as per one embodiment, the frame structure (200) also includes a rear compartment that supports a cabin assembly (109), and an engine (111) which is substantially disposed in the rear side of motor vehicle (fig. 1a).
[00032] Fig. 3 is a partial perspective view of a motor vehicle having driver seat assembly in opened condition and Fig. 3a is a bottom side view of a driver seat assembly, as per one embodiment of the present invention along with a local illustration of the sub-assembly of driver seat frame assembly (304) and driver seat reinforcing assembly (303). As per one embodiment of the present invention, the driver seat assembly (104) includes a drive seat (302), a driver seat frame assembly (304), a driver seat reinforcing assembly (303). The driver seat frame assembly (304) includes a pair of lateral members (304a, 304a’), a pair longitudinal members (304b, 304b’), a pair of bridge members (304c, 304c’) and a vertically downwardly extending member (304d) from the pair of bridge member, where the pair of lateral members (304a, 304a’), the pair longitudinal members (304b, 304b’), the pair of bridge members (304c, 304c’) and the vertically downwardly extending member (304d), are fixedly attached with each other. The pair of lateral members (304a, 304a’) and longitudinal members (304b, 304b’) are supported on body of the vehicle. The vertically downwardly extending member (304d) is housed and attached with various attachment means, for example fasteners, on the top of the central frame member (203) and a pair of LH (left hand) side frame member (205) and RH (right hand) side frame member (202) of the frame structure (200). As per one embodiment of the present invention, the driver seat reinforcing assembly (303) is attached with the driver seat (302) with various attachment means, for example, fasteners. The driver seat (302) is attached on the driver seat frame assembly (304) through the driver seat reinforcing assembly (303). A protective shield (307) is disposed under the driver seat assembly (304) for securely protecting the power storage device housing area (110) where one or more stack of energy storage device (301) is placed.
[00033] As per one embodiment of the present invention, the driver seat reinforcing assembly (303) includes a lateral member (303a) attached with driver seat (302), a pair of longitudinal members (303b, 303b’) extending forwwardly from the lateral member (303a). The pair of longitudinal members (303b, 303b’) are fixedly attached with the lateral member (304a’) of the driver seat frame assembly (304) with various means, for example, a pair of C shaped brackets (306a, 306b). The drive seat assembly (104) includes multiple clamping members (305a, 305b, 305c, 305d) which clamps the driver seat (302) with the driver seat reinforcing assembly (303) with various means, for example, fasteners. This configuration ensures stable mounting of the driver seat assembly (104) and enables opening of the driver seat (302) by forming acute angle ‘A’ with respect to driver seat frame assembly of the vehicle, thus ensuring ease of accessibility of the one or more stack of energy storage device accommodated under the driver seat. This configuration ensures that while pulling out/taking out the one or more stack of energy storage device (301), hand of the user does not interfere with the driver seat or any other surrounding components. Further, the present configuration eliminates the requirement of dedicated lock and key required to lock the driver seat assembly (104). This configuration also ensures theft proof accommodation of the stack of energy storage device (301) under the driver seat as the pair of C shaped brackets (306a, 306b) restrict unauthorized access of the driver seat assembly (104) by a user other than the authorized user, from front side of the vehicle. The present configuration also eliminates the requirement of additional number of attachment means, for example, fasteners, for attaching the driver seat with the driver seat frame assembly, thus reducing the number of part counts and being cost effective.
[00034] Fig. 4 is a partial front left perspective view of a vehicle with housing assembly of one or more stack of energy storage device and Fig 4a is a perspective view of the housing assembly, as per one embodiment of the present invention. As per one embodiment of the present invention, the one or more stack of energy storage device (301) is housed in a housing assembly (401) and covered by the protective shield (307) in the vehicle. The housing assembly (401) includes multiple base members (402a, 402b, 402c, 402d), two pairs of upwardly extending members (403a, 403b; 403c, 403d), plurality of guide members (407a, 407b) and two pairs of vertically upwardly extending members (404a, 404b; 404c, 404d). The multiple base members (402a, 402b, 402c, 402d) attach the housing assembly (401) to the frame structure of the vehicle with various means, for example, fasteners (408). The frame structure of the vehicle absorbs weight of the one or more stack of energy storage device (301). The two pairs of upwardly extending members (403a, 403b, 403c, 403d) are V shaped when viewed from side of the vehicle, are disposed at extreme end of the housing assembly. The two pairs of upwardly extending members (403a, 403b, 403c, 403d) acting as a supporting member/locating member for the one or more stack of energy storage device while accommodating into the housing assembly. The plurality of guide members (407a, 407b) are U shaped when viewed from top of the vehicle, are disposed between the one or more stack of energy storage device, ensuring cooling of the stack of energy storage device through atmospheric air. The two pairs of vertically upwardly extending members (404a, 404b, 404c, 404d) are disposed between the plurality of guide members (407a, 407b) and the two pairs of upwardly extending members (403a, 403b, 403c, 403d). The two pairs of vertically upwardly extending members (404a, 404b, 404c, 404d) include two pairs of holding brackets (405a, 405b, 405c, 405d). The two pairs of holding brackets (405a, 405b, 405c, 405d) includes a pair of locking mechanisms (406a, 406b) extending inclinedly upwardly and then laterally, from the two pairs of holding brackets (405a, 405b, 405c, 405d), ensuring locking and ease of assembly of the one or more stack of energy storage device (301) in the housing assembly (401). The locking mechanisms (406a, 406b) includes a belt and toggle clamp, where the belt is locked in toggle clamp and thus, locks the one or more stack of energy storage device (301) with the housing assembly (401). This configuration also provides stable housing of the one or more stack of energy storage device (301) in the housing assembly (401) while eliminating requirement of additional attachment means.
[00035] The invention helps in overcoming the problem of accessibility of the one or more stack of energy storage device when the driver seat is in open condition, while maintaining the anti-theft property of the one or more stack of energy storage device and maintaining the overall weight and width of the stock vehicle and ultimately makes it cost effective.
[00036] Advantageously, the embodiments of the present invention, describes the potential modifications in the driver seat assembly and mounting of one or more stack of energy storage device in the vehicle.
[00037] Many other improvements and modifications may be incorporated herein without deviating from the scope of the invention.

List of reference symbol:
Figure 1:
100: Motor Vehicle
106: Handle Bar Assembly
101: Front Wheel
104: Driver Seat Assembly
105: Driver back rest
102: Rear Wheels
103: Front Fender
110: Power Storage Housing Area
108: Passenger Seat Assembly
107: Passenger Barrier.
109: Cabin Assembly
111: Internal Combustion Engine
Figure 2:
200: Frame structure
201: Head Tube
206: Main Tube
203: Central frame member
205: LH Side frame member
202: RH Side fame member
204: Cross frame member
Figure 3:
301: One or more stack of energy storage device
302: driver seat
303: Driver Seat Reinforcing assembly
304: Driver seat frame assembly
307: Protective Shield
.
A: Acute angle
Fig. 3a
303a: a lateral member
303b, 303b’: Pair of longitudinal members
304a, 304a’: pair of lateral members
304b, 304b’: pair longitudinal members
304c, 304c’: pair of bridge members
304d: vertically downwardly extending member
305 (305a, 305b, 305c, 305d): Multiple clamping members
306a, 306b: C shaped Bracket
Fig 4:
401: Housing Assembly
402a, 402b, 402c, 402d: Multiple Base Members
403a, 403b; 403c, 403d: two pairs of upwardly extending members
404a, 404b; 404c, 404d: two pairs of vertically upwardly extending members
408: Fasteners
407a, 407b: plurality of guide members
405a, 405b; 405c, 405d: two pairs of holding brackets
406a, 406b: a pair of locking mechanisms.

,CLAIMS:WE CLAIM:
1. A motor vehicle (100), said vehicle (100) comprising:

a frame structure (200) providing skeletal support to said vehicle (100);
a driver seat assembly (104) mounted on said frame structure (200);
said driver seat assembly (104) includes a driver seat frame assembly (304), a driver seat reinforcing member assembly (303) and a driver seat (302), wherein said driver seat (302) being attached to said driver seat frame assembly (304) and said driver seat reinforcing member (303);
a one or more stack of energy storage device (301) being disposed under said driver seat (302), said one or more stack of energy storage device (301) being located in a housing assembly (401);
said housing assembly (401) being provided with a pair of locking mechanisms (406a, 406b), said pair of locking mechanism (406a, 406b) being detachably attached with said frame structure (200) of said vehicle.
2. The motor vehicle (100) as claimed in claim 1, wherein said driver seat assembly (104) includes multiple clamping members (305a, 305b, 305c, 305d) for clamping said driver seat (302) with said driver seat reinforcing assembly (303).
3. The motor vehicle (100) as claimed in claim 1, wherein said driver seat frame assembly (304) includes a pair of lateral members (304a, 304a’), a pair longitudinal members (304b, 304b’), a pair of bridge members (304c, 304c’) and a vertically downwardly extending member (304d), wherein said pair of lateral members (304a, 304a’) and said pair longitudinal members (304b, 304b’) being supported on said vehicle; and said vertically downwardly extending member (304d) being attached to said frame structure (200).
4. The motor vehicle (100) as claimed in claim 1, wherein said driver seat reinforcing assembly (303) includes a lateral member (303a) and a pair of longitudinal members (303b, 303b’), said pair of longitudinal members (303b, 303b’) extending forwardly from said the lateral member (303a); and wherein said lateral member (303a) being attached with said driver seat (302).
5. The motor vehicle (100) as claimed in claim 4, wherein said pair of longitudinal members (303b, 303b’) being attached with a lateral member (304a’) of said driver seat frame assembly (304), said attachment being through a pair of C shaped brackets (306a, 306b).
6. The motor vehicle (100) as claimed in claim 1, wherein said housing assembly (401) includes multiple base members (402a, 402b, 402c, 402d), two pairs of upwardly extending members (403a, 403b; 403c, 403d), a plurality of guide members (407a, 407b) and two pairs of vertically upwardly extending members (404a, 404b; 404c, 404d).
7. The motor vehicle as claimed in claim 6, wherein said multiple base members (402a, 402b, 402c, 402d) being configured to attach said housing assembly (401) with said frame structure (200).
8. The motor vehicle as claimed in claim 6, wherein said two pairs of upwardly extending members (403a, 403b; 403c, 403d) being V shaped when viewed from side of said vehicle (100).
9. The motor vehicle as claimed in claim 6, wherein said two pairs of upwardly extending members (403a, 403b; 403c, 403d) being disposed at extreme end of said housing assembly (401).
10. The motor vehicle as claimed in claim 6, wherein said plurality of guide members (407a, 407b) being U shaped when viewed from top of said vehicle (100).
11. The motor vehicle as claimed in claim 6, wherein said two pairs of vertically upwardly extending members (404a, 404b; 404c, 404d) being disposed between said plurality of guide members (407a, 407b) and said two pairs of upwardly extending members (403a, 403b; 403c, 403d).
12. The motor vehicle as claimed in claim 6, wherein said two pairs of vertically upwardly extending members (404a, 404b; 404c, 404d) includes two pairs of holding brackets (405a, 405b; 405c, 405d), wherein said two pairs of holding brackets (405a, 405b; 405c, 405d) includes said pair of locking mechanisms (406a, 406b), said pair of locking mechanisms (406a, 406b) extending inclinedly upwardly and then laterally for locking stack of one or more energy storage device (301).
13. A driver seat reinforcing member (303) for a driver seat assembly (104) for a motor vehicle (100), said reinforcing member comprising:
a lateral member (303a);
a pair of longitudinal members (303b, 303b’);
said lateral member (303a) being attached to a drive seat (102) of said driver seat assembly (104),
said pair of longitudinal members (303b, 303b’) being fixedly attached with a driver seat frame assembly (304).

14. The driver seat reinforcing assembly (303) as claimed in claim 13, wherein said pair of longitudinal members (303b, 303b’) being fixedly attached with a lateral member (304a’) of said driver seat frame assembly (304) through a pair of C shaped brackets (306a, 306b).