DESC:FIELD OF INVENTION

The present invention relates to a latching system to be used for mechanically locking the tiltable cabins for medium and heavy duty truck-cabins. In particular, present invention relates to a two-point suspended tiltable cabin. More particularly, the tilted truck cabin can be mechanically latched by using the torsion bar as well as cylinder-actuated hydraulic system.

BACKGROUND OF THE INVENTION

Automotive vehicles, such as buses, trucks and trailers are the backbone of the modern public and goods transportation Industry. The commercial vehicles are divided into light, medium duty and heavy duty vehicles. However, medium duty and heavy duty trucks are very important class of vehicles for goods transportation. The heavy duty trucks are used for transporting goods across very long distances, while the medium duty trucks are used for intra/inter-city transportation of goods.

For facilitating the ease of engine maintenance, nowadays the truck cabins are often made tiltable. So, these cabins can be tilted as and when required for accessing engine compartment for any maintenance/servicing activities.

DISADVANTAGES WITH THE PRIOR ART

The following are the disadvantages with the cabin tilting systems available in the market today:

The vehicles currently available in the market have both hydraulic and mechanical systems for tilting the cabin. The hydraulic system utilizes a hydraulic pump and cylinder for tilting the cabin of the truck, whereas, the mechanical suspension system for tilting the truck cabins, a number of configurations are available in the market.

However, such systems are complex in construction and upkeep and also very heavy to handle. Such mechanical systems are also not easy to operate.
Thus, there is an existing need for an improved tilted cabin system for trucks, which can avoid the shortcomings enumerated above.

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 system for secure locking of a truck cabin with a vehicle ladder frame.

Another object of the present invention is to provide a system, which can easily unlock the cabin and allow it to tilt about the axis thereof.

Still another object of the present invention is to provide a 2-layer safety measure to the occupants in case of accidental tilting while driving.

Yet another object of the present invention is to provide a technical solution to prevent latch locking when the cabin is already tilted.

Yet another object of the present invention is to provide a technical solution to prevent latch locking when the cabin is already tilted.

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. However, the embodiments represented herein are 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 mechanical latching system mounted in a two-point suspended cabin for tiltable cabin, the latching system comprises:
• a pair of latch assemblies connected by a spring to provide a relative motion therebetween;
• connecting rod connecting the pair of latch assemblies;
• a latch handle rotatable about the handle pivot pin;
• a latch actuation pin;
• latch skin;
• a fixed axis arm;
• two freely rotating arms;
• a handle lock and a secondary lock; and
• a bottom striker;

wherein the latch system is mounted in the cabin tiltable by using the latch handle from latch open position via an intermediate position to a latch closed position or vice-versa by transferring the motion of the latch handle through the latch actuation pin by using a relative motion between a fixed axis rotating arm and a freely rotating arm.

Typically, the latch system comprises a two part assembly consisting of a latch actuation system and a locking system.

Typically, the latch assemblies are fixed to the truck cabin and the latch actuation system is mounted on the truck cabin.

Typically, the two-part assembly forms a close-loop to be used as a holding device for bottom striker having an open-profile; the two free rotating arms joined by a lock pin form a closed-loop rotating about a pivot pin of the fixed axis arm.

Typically, the close-loop is configured as the bottom striker and the open-profile is configured on the latch side for locking the cabin.

Typically, the bottom striker is an open-profile fixed to chassis side and is configured in question mark shape to be bolted or welded to cabin mounting bracket.

Typically, the closed-loop is configured on the chassis side and open-profile on the cabin side to facilitate the locking of the cabin with the frame ladder of the vehicle.

Typically, the actuation system comprises a handle rotatable about the handle pivot pin from an opened to a closed position or vice versa and a spring is provided to push open in the direction of the spring force for unlocking the cabin.

Typically, a secondary lock is configured as a safety in case of failure of the primary lock or in case of latch remaining locked after the cabin being in ready-for-driving condition.

Typically, a second level of locking is provided in case of failure of the primary function of the latch, the secondary lock forms part of the actuation system and locks the cabin with vehicle frame ladder by using a solid rod welded to cabin mountings.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

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

Figure 1 shows a schematic representation of the entire latch system in accordance with the present invention depicted in a front view.

Figure 2 shows a schematic representation of the actuation system for opening the tilt latch of the cabin.

Figure 3 shows a schematic representation of the latch in open condition and the motion path for latch skin from the open condition to closed condition.

Figure 4 shows an enlarged view of the latch system depicted in Figure 3.

Figure 5 shows a schematic representation of the latch in closed condition and the motion path for latch skin from the open condition to closed condition.

Figure 6 shows an enlarged view of the latch system depicted in Figure 5.

Figure 7 shows a schematic representation of the latch in the motion path for latch skin from the open condition to closed condition.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, the mechanically operated latching system for locking tiltable cabins of medium and heavy duty truck-cabins configured in accordance with 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.

Accordingly, the present invention provides a mechanically operated latching system for locking tiltable cabins of medium and heavy duty truck-cabins. Particularly, the invention provides a two-point mechanical suspended tiltable cabin equipped with such a tilting and latching system. In this tilt latch system, the truck cabin can be mechanically tilted by using the torsion bar and a cylinder-actuated hydraulic system and securely locked in a desired position. The system has proven to be extremely effective for tilting the cabins of medium and heavy duty trucks.

Figure 1 shows a schematic representation of the complete latch system in accordance with the present invention depicted in a front view illustrating its important features. Accordingly, the latch system 21 includes a latch actuation system 20 with a left hand (LH) latch assembly 11 and right hand (RH) latch assembly 12 each and connecting rod 7 for simultaneously actuating these LH and RH latch assemblies 11, 12. The latch system 21 is shown (in dark black colour) in its environment (shown in light grey colour) along with various other parts of the cabin tilt latch arrangement which are not necessarily part of the present invention. The latch system 21 can be mounted in a truck cabin 13, which can be tilted. The cabin tilting operation can be performed by using a torsion bar or hydraulic system (not shown). The figure also shows the method of fitting this latch system 21 in a truck cabin. Each latch assemblies 11, 12 are fixed to the cabin and the latch actuation system 20 is mounted on this cabin. Further, the latch system 21 is mounted in a truck cabin 13 equipped with an engine 14 and cabin mountings 15 on which cabin rests with vehicle ladder frame (not shown). The bottom striker 16, hook 19 and latch actuation system 20 are also provided in the latch system 21 along with the torsion bar17, hydraulic tilting mechanism 18 and cabin mountings 15.

Figure 2 shows a schematic representation of the latch actuation system 20 accordance with the present invention depicted in both open (A) and closed (C) positions. The springs are used for movement of the parts from one position to the other. The latch system 21 consists of a latch handle 1 rotating about the handle pivot pin 2, a handle lock 3 and a secondary lock 4. Here, the latch handle 1 is shown in three different positions. The top position A is latch open position and bottom position C is latch closed position. As handle 1 is moved downward, it pushes the pin of handle lock 3 and which in turn gets locked, as shown in figure. The movement of the latch handle transfers the motion from the handle 1 to the connecting rods 7. These connecting rods 7 are connected to the LH latch assembly 11 and RH latch assembly 12 through the latch actuation pin 6 (Figures 3 and 4). So, the motion of the handle 1 is transferred to the latch actuation pin 6. There are two portions in the latch system 21 and a spring is connected to provide a relative motion between these parts. A fixed axis rotating arm 8 has one side fixed axis and other side is connected to freely rotating arm.

Figure 3 shows a schematic representation of the latch in an open condition. In this condition, the substantially ‘L’ shaped handle 1 has a longer arm in raised position and a shorter arm connected to the connecting rod 7. The handle 1 can be swiveled about a pivot pin 2 to simultaneously move the latch assemblies disposed on either side of the latch system 21. The handle lock 3, the secondary lock 4, latch skin 5, latch actuation pin 6, connecting rod 7, rotating arm 8, freely rotating arm 9 and a locking pin 10 are also shown here. The latch is depicted in an open condition and the locking pin 10 is not depicted in engagement with the bottom striker 16.

Figure 4 shows an enlarged view of the latch system depicted in Figure 3. Here, the locking pin 10 is not depicted in engagement with the bottom striker 16. A close-loop is made in the cabin side and an open-profile is made in the frame side. By moving the closed-loop part facilitates in locking of the latch system 21 in the open-loop and this way, a complete latching of the truck cabin 13 is realized. This can also be done in a reverse manner, in which a closed-loop having a locking pin 10 is fixed to chassis side of the truck and a moving open-profile gets locked due to the motion transferred by handle 1.

Figure 5 shows the locking position of locking pin 10, when an effort is applied and either the truck cabin is tilted or there is no bottom striker 16 to block the path of locking pin 10. This is a very usual scenario occurring when the latch is getting locked and the truck cabin 13 is in a tilted condition. This leads to either failure or bending of the latch when cabin is being brought its tilted position to the normal position on the chassis and inadvertently hits to system. Using the curved profile, a lock is made to stop the movement of the locking pin 10 and this in turn stops the movement of latch handle 1. On applying further force the handle 1 will not generate any movement of the parts.

Figure 6 shows a schematic representation of the latch system 21 in accordance with the present invention with the locking pin 10 is in locked position with the bottom striker 16 and it will not be able to move further. In this position, a closed loop is made in the cabin side and an open loop is made in the frame side. The moving closed loop part is getting locked in open loop and this way complete latching of the truck cabin occurs. This can also be done in reversed way, wherein a closed loop having looking pin 10 is fixed to the chassis side and an open loop which is moving gets locked due to the motion transferred by the handle 1.

Figure 7 shows an enlarged view of the latch system depicted in Figure 6. Here, the locking pin 10 is securely sitting in the bottom striker 16. In the present embodiment, a latch system 21 is used, which is housed in the underbody side of cabin 13 and the bottom striker 16 used for holding the latch can be kept at the vehicle ladder frame side. The latch system 21 is a very critical part for the safety of the cabin occupants, because it holds the cabin 13 having a tendency of rotating about its axis either due to torsion effect of the torsion bar 17 or because of the vehicle braking force. The rotation of the cabin 13 may lead to the cabin occupants falling on windshield glass and vehicle may go out of their control. In order to prevent this situation, the cabin latch system 21 has additional locking arrangements to provide another layer of safety to the cabin occupants, i.e. a 2-layer safety.

In the present invention, complete system is divided into two main categories. One is actuation system and the other is locking system.

The actuation system is used to transfer the force applied by the user/s from the actuation system to the locking system. This is accomplished by using a handle 1, which rotates about a pivot pin 2 and traces the open or closed position. It also includes a provision for locking of handle 1, when cabin 13 is locked. It has a spring, which pushes it to open in the direction of the spring force, when it is intended to unlock the cabin 13. It also includes a secondary locking measure, which is a safety aspect required in case of failure of the primary lock or in case of forgetting to latch lock after the cabin is in ready-for-driving condition.

Another important part is locking system which includes a two-part assembly, the object of which is to form a close-loop. This close-loop is used as a holding device for bottom striker 16. Bottom striker 16 has an open-profile.

This combination can also be reversed. So, the close-loop can also be made as bottom striker and the open-profile can be kept on the latch side. This way cabin 13 can be locked.

Description of latch locking of cabin by the latch system in accordance with the present invention:

Latch system 21 for automotive vehicles is mounted on a truck cabin 13 consisting of a rear wall, a front Panel, windshield glass and at least two doors. Cabin 13 is tilted by using torsion bar 17 or hydraulic cylinder 18 (not shown being part of the environment). Latch system 21 is used for tilting the cabin to access engine compartment area. It consists of a latch system 21 and an actuation system 20, connecting rods 7 and a fixed axis rotating arm 8 and a freely rotating arm 9. The latch system 21 includes two free rotating arms 9 joined by using a lock pin 10 and thus forming a closed-loop, which rotates about a pivot pin of the fixed axis rotating arm 8. This close-loop is locked by a bottom striker 16, which is an open-profile fixed to chassis side. This has a question mark shape, which may be bolted or welded to cabin mounting bracket 15. The latch system 21 can also have an open profile of a freely rotating arm 9 in the cabin side and a loop in the side of the bottom striker 16.

A reverse configuration by keeping the closed-loop on the chassis side and open-profile on the cabin side can also facilitate in locking the cabin with the frame ladder of the vehicle. The latch system 21 has a fool-proof system against abusive use of the latch. Sometimes, the latch is locked by using handle 1, while cabin is still in a tilted condition. Once cabin is dropped from this condition, it will damage the cabin latch. To protect it from this situation, the latch locking pin 10 hits the profile of the latch cover, when bottom striker 16 is not present or when the cabin is still in a tilted condition.

The latch system 21 also includes the provision of second level of locking in case of failure of the primary function of the latch. This secondary lock 4 is a part of the latch actuation system 20 and it locks the cabin with the vehicle frame ladder by using a solid rod welded to cabin mountings 15 (not shown being part of the environment).

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The mechanical latching system for two-point suspended cabin configured in accordance with the present invention has the following advantages:

• Facilitates secure locking of the truck cabin with a vehicle ladder frame.
• Enables easy unlocking the cabin to allow tilting about its axis.
• Provides 2-layer safety measure avoid accidental tilting during driving.
• Prevents latch locking in cabin already tilted truck cabin.

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, it does not imply excluding any other element, integer or step, or group of elements, integers or method steps. In the claims and the description, the terms “containing” and “having” are used as linguistically neutral terminologies for the corresponding terms “comprising”.

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. Furthermore, the use of the term “one” shall not exclude the plurality of such features and components described.

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. In the previously detailed description, different features have been summarized for improving the conclusiveness of the representation in one or more examples. However, it should be understood that the above description is merely illustrative, but not limiting under any circumstances. It helps in covering all alternatives, modifications and equivalents of the different features and exemplary embodiments.

Many other examples are directly and immediately clear to the skilled person because of his/her professional knowledge in view of the above description. 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.

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.

The exemplary embodiments were selected and described in order to be able to best represent the principles and their possible practical application underlying the invention. Thereby, the skilled persons can optimally modify and use the invention and its different exemplary embodiments with reference to the intended use. ,CLAIMS:We claim:

1. A mechanical latching system mounted in a two-point suspended cabin for tiltable cabin, the latching system comprises:

• a pair of latch assemblies connected by a spring to provide a relative motion therebetween;
• connecting rod connecting the pair of latch assemblies;
• a latch handle rotatable about the handle pivot pin;
• a latch actuation pin;
• latch skin;
• a fixed axis arm;
• two freely rotating arms;
• a handle lock and a secondary lock; and
• a bottom striker;

wherein the latch system is mounted in the cabin tiltable by using the latch handle from latch open position via an intermediate position to a latch closed position or vice-versa by transferring the motion of the latch handle through the latch actuation pin by using a relative motion between a fixed axis rotating arm and a freely rotating arm.

2. Mechanical latching system as claimed in claim 1, wherein the latch system comprises a two part assembly consisting of a latch actuation system and a locking system.

3. Mechanical latching system as claimed in claim 1, wherein the latch assemblies are fixed to the truck cabin and the latch actuation system is mounted on the truck cabin.

4. Mechanical latching system as claimed in claim 2, wherein the two-part assembly forms a close-loop to be used as a holding device for bottom striker having an open-profile; the two free rotating arms joined by a lock pin form a closed-loop rotating about a pivot pin of the fixed axis arm.

5. Mechanical latching system as claimed in claim 4, wherein the close-loop is configured as the bottom striker and the open-profile is configured on the latch side for locking the cabin.

6. Mechanical latching system as claimed in claim 4, wherein the bottom striker is an open-profile fixed to chassis side and is configured in question mark shape to be bolted or welded to cabin mounting bracket.

7. Mechanical latching system as claimed in claim 4, wherein the closed-loop is configured on the chassis side and open-profile on the cabin side to facilitate the locking of the cabin with the frame ladder of the vehicle.

8. Mechanical latching system as claimed in claim 1, wherein the actuation system comprises a handle rotatable about the handle pivot pin from an opened to a closed position or vice versa and a spring to push open in the direction of the spring force for unlocking the cabin.

9. Mechanical latching system as claimed in claim 8, wherein a secondary lock is configured as a safety in case of failure of the primary lock or in case of latch remaining locked after the cabin being in ready-for-driving condition

10. Mechanical latching system as claimed in claim 9, wherein a second level of locking is provided in case of failure of the primary function of the latch, the secondary lock forms part of the actuation system and locks the cabin with vehicle frame ladder by using a solid rod welded to cabin mountings.

Dated: 31st March, 2015 SANJAY KESHARWANI
APPLICANT’S PATENT AGENT