DESC:FIELD OF INVENTION

The present invention generally relates to an automobile body-in-white (BIW) transfer mechanism. In particular, the present invention relates to a pneumatically-operated automobile BIW transfer mechanism. More particularly, the present invention relates to a transfer mechanism actuated by compressed air to optimally transfer an automobile BIW from one workstation to another covering the minimum distance.

BACKGROUND OF THE INVENTION

In automobile manufacturing plants, body-in-white is the major sub-assembly, which needs to be transferred from one workstation to another one for carrying out diverse machining, welding, painting and allied operations thereon. At present, this BIW transfer from one workstation to another is done manually as illustrated Figure 1.

Generally, the total span for pushing the BIW manually is about 28 m, in overall framing domain. This span involves a total of four (4) work stations for conducting spot-welding of sheet metal BIW. Normally, two operators are required to manually push the BIW weighing about 160 kg, from one of these workstations to another.

PRIOR ART

The existing mechanisms available in automobile manufacturing plant of OEMs including those of the applicant’s various manufacturing facilities, include the following BIW transfer mechanisms:

The shuttle transfer system involves a rack and pinion drive or gear drive used for linear transfer of BIW from one workstation to another, which is actuated by a servo motor control and the vertical motion of BIW is achieved by means of a hydraulic cylinder.
This system includes complex devices such as servo motor, latch switches, photo sensors, feedback devices, limit switches, messaging protocol system, remote input and output devices etc.

The complete shuttle transfer system is integrated to PLC (programmable logic control) and involves major capital investment. Here, BIW is placed on the carrier skids which are interconnected throughout the manufacturing line. The lower section carrier skids are in turn attached to the rack and pinion drive operated by means of a servo controlled motor, which is programmed and connected to the PLC server.

Once motor is triggered to operate, it actuates the hydraulic cylinders to lift BIW from the carrier skid and then linearly transfers BIW from one workstation to another. After completion of the linear transfer, the hydraulic cylinders are deactivated to lower BIW on fixture mylers. Then, spot welding of BIW is carried out and after completing this spot welding, the abovementioned cycle is repeated.

The publication US 5141093 A, titled - “Automotive body panel handling apparatus” discloses an apparatus for conveying panels, such as vehicle body side panels to and from work stations located at spaced locations along a conveyor includes a panel support frame mounted on the conveyor for movement along the conveying path with the support frame in an elevated generally horizontal conveying position. The support frame carries a plurality of mechanically actuated releasable clamps adapted to retain a panel engaged against a group of locator pads fixedly mounted on one side of the support frame. A second group of locator pads movably mounted on the frame are normally biased into engagement with the panel at spaced locations around its periphery to hold the panel in a predetermined position laterally of the support frame. The support frame mounts an actuator member coupled to all of the clamps to position all clamps in a panel clamping position when the actuator member is in a first position and to position all clamps in a panel release position when the actuator is in a second position. Here, a spring biased latch on the support frame normally locks the actuator member against movement from either of its positions. The conveyor includes a manipulator operable when the support frame is at a work station to pivot the support frame downwardly from its conveying position to a downwardly inclined transfer position. Actuating devices located at the work station are operable when the support frame is in its transfer position to release the latch, disengage the movable locator pads and shift the clamp actuator member between its first and second positions.

The publication CN 105904127 A, titled - “Flexible transferring production line for car body” discloses a flexible transferring production line for a car body. The flexible transferring production line comprises a corresponding number of work stations arranged fitting welding procedures and a reciprocating rod mechanism which extends and covers all of the work stations, wherein the reciprocating rod mechanism is driven through a servo driving mechanism; each work station is provided with a support base, a flexible positioning mechanism is mounted on each support base, and a roller guide mechanism is mounted in the middle of each support based; and the reciprocating rod mechanism is mounted on the roller guide mechanisms, and the reciprocating rod mechanism is provided with a transferring positioning mechanism corresponding to each work station. After a car body workpiece is welded under the support of the flexible positioning mechanism, the flexible positioning mechanism falls. The car body workpiece falls on the corresponding transferring positioning mechanism after falling for 0.5mm to 1mm, and the flexible positioning mechanism continuously falls. The servo driving mechanism drives a reciprocating rod to move to the next work station, and the flexible positioning mechanism at the next work station rises. After the car body workpiece is supported, welding work at the next work station is carried out, and the reciprocating rod mechanism returns to the original work station to await orders. Work is cyclically carried out in this way.

The publication US 3247984 A, titled - “Vehicle body for materials handling” relates to vehicle bodies for materials handling and particularly to the construction and arrangement of the materials handling means mounted for relative motion on a vehicle body for either compressing a load or for expulsing a load from the body as when unloading dirt or other materials, like garbage, which is not at all applicable to present invention.

The publication WO 2015010534 A1, titled - “Vehicle carrying position mechanism” discloses a vehicle carrying transmission platform, a frame and a drive mechanism. The vehicle carrying transmission platform comprises a carrier roller assembly and a conveyer belt arranged thereon, and two edge beam assemblies consisting of an inner edge beam and an outer edge beam respectively. The inner edge beam and the outer edge beam are respectively provided with baffle plates for blocking wheels in an integral formation. The baffle plates are respectively provided with several mounting positions at inner side thereof correspondingly. The mounting positions are respectively provided with a bearing seat. The two ends of the carrier roller assembly are rotatably arranged on the two corresponding bearing seats, respectively. The frame comprises several cross beams fixedly connected between the two edge beam assemblies. The vehicle carrying position mechanism improves assembling efficiency, and enhances the strength of the edge beam assemblies and the baffle plates simultaneously.

DISADVANTAGES WITH PRIOR ART

The following are the disadvantages with the prior arts discussed above:

• None of these transfer mechanisms can be used here, as each workstation has vertical up and down motion achieved through scissor lift operated by a hydraulic system.

• A multi-variant managing production line, purely operated on manual controls, needs to be equipped with the available advanced technology, which involves heavy capital investment.

• Retrofitting of the existing transfer mechanisms with advance technology also requires a total reconstruction of the automobile manufacturing plant’s layout.

Accordingly, there exists a need to provide a system to address the above challenges related to a cost-effective solution which also enables ease of accessibility and serviceability, without significantly affecting the existing BIW production line layout and process characteristics.
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 cost-effective and improved BIW transfer mechanism for automobile manufacturing plants.

Another object of the present invention is to provide an improved BIW transfer mechanism for automobile manufacturing plants, in which BIWs need to cover a minimum distance between the workstations.

Still another object of the present invention is to provide an improved BIW transfer mechanism for automobile manufacturing plants, which requires least changes for retrofitting it in the existing manual BIW transfer mechanisms.

Yet another object of the present invention is to provide an improved BIW transfer mechanism for automobile manufacturing plants, which facilitates in ease of access and serviceability thereof.

A further object of the present invention is to provide an improved BIW transfer mechanism for automobile manufacturing plants, which eliminates manual pushing of BIWs between various workstations.

A still further object of the present invention is to provide an improved BIW transfer mechanism for automobile manufacturing plants, which prevents damages to the BIWs during transfer from one workstation to the other.

A yet further object of the present invention is to provide an improved BIW transfer mechanism for automobile manufacturing plants, which removes the bottlenecks in the process-line to increase the productivity thereof and that too without making any major change in the process-line.

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.

DESCRIPTION OF THE INVENTION

In accordance with the present invention, a simple, improved and cost-effective solution for existing BIW pushing system is provided, which comprises using a pneumatic mechanism, preferably a mechanism actuated by compressed air, in which two pneumatic cylinders are used in conjunction to achieve the displacement of about 6 m to transfer BIW from one workstation to another.

This pneumatic mechanism is complemented by a quick exhaust valve in order to overcome the redundant inertia existing in the mechanical systems thereof. The array of pneumatic cylinders is stationed to integrate the displacement with each stage of BIW pushing operation. By pushing one pneumatic valve lever by the operator, BIW can easily be automatically displaced over an optimum span of about 6.5 m. Thus, the total pushing effort is reduced from 24 kg to 24 g. In fact, three pneumatic cylinders are used in this system, two of which have stroke lengths of 2000 mm and 50 mm respectively and the remaining one is a rotary cylinder having an angular displacement of 900. The cylinder having stroke length 50 mm and the rotary cylinder with angular displacement are mounted over trolley in a back-to-back configuration, which in turn is mounted over bearing wheels.

SUMMARY OF THE INVENTION

In accordance with the first embodiment of the present invention, there is provided a pneumatic mechanism for transferring body-in-white (BIW) between workstations in an automobile manufacturing plant, the BIW transfer mechanism comprising:

• a plurality of pneumatic cylinders for carrying out a dual phase operation to optimally transfer the BIW from one workstation to another;

• at least one quick exhaust valve provided for the pneumatic cylinder;

• a source to supply compressed air to operate the pneumatic cylinders;

• atleast one flow control valve to regulate compressed air flow to each of the pneumatic cylinders; and

• a plurality of pilot valves;

wherein the operation of the pneumatic Body-In-White (BIW) transfer mechanism is governed by manual and fail/safe pilot actions performed by the pilot valves to activate or deactivate the pneumatic BIW transfer mechanism.

Typically, the plurality of pneumatic cylinders comprises a principal cylinder; a primary actuation cylinder for a first traverse and a rotating cylinder for second traverse, the primary and rotary cylinders mounted over BIW trolley in back to back pattern and the trolley mounted over bearing wheels.

Typically, the primary cylinder is a linearly operated and the secondary cylinder is a rotary cylinder actuated by a lever valve.

Typically, the rotary cylinder is mounted over the yoke of the primary cylinder and the operation of both the cylinders is routed through two of the pilot valves interconnected and governed through manual and fail/safe actions to activate or deactivate the BIW transfer mechanism.

Typically, the quick exhaust valve is installed at the mounting point of the primary cylinder end and said flow control valve is provided to regulate the flow rate of compressed air.

Typically, the fail/safe pilot mechanism is installed with protocols to trigger the operation of the BIW transfer mechanism to standstill condition, when the override function of the BIW transfer mechanism is executed.
Typically, the rotary secondary cylinder is connected to an impact bar used for pushing the BIW during the second phase of transfer thereof from one workstation to another.

Typically, the BIW is propelled with reference to the cross member in the first phase and pushed from the under the BIW by using the linearly operated primary cylinder and rotary secondary cylinder; and the rotary cylinder is in a standstill position.

Typically, a bearing trolley mounted structure is provided having two cylinders actuated by means of the primary cylinder for locating the bearing mounted structure under the BIW.

Typically, the primary cylinder is actuated to bring home the bearing trolley mounted structure; and the linearly operated primary cylinder and rotary secondary cylinder is in standstill position and rests on a chucker plate platform.

Typically, the front side of the BIW is propelled by actuating the swing rod attached at the front end of the rotary cylinder and a limit switch triggers the quick exhaust valve to move the BIW in this second phase.

Typically, the linearly operated cylinder is in standstill position and the rotary cylinder is actuated by rotating a lever valve connected to an impact bar to push the BIW in its final position and the primary cylinder is actuated to bring it in home position.

In accordance with the second embodiment of the present invention, there is provided a BIW transfer mechanism comprising:

• a principal cylinder having the largest stroke length;

• at least one linearly operated pneumatic cylinder; preferably a primary and a secondary pneumatic cylinder each;

• a rotary pneumatic cylinder having an extended shaft end;

• an L-type mounting plate for mounting both the linearly operated cylinder and the rotary cylinder;

• the rotary cylinder mounted on the L-type mounting plate supported on bearings fitted on a bearing spindle;

• an impact bar mounted on the extended shaft end by means of a mounting bolt; and

• an end plate connector on the L-type mounting plate and disposed between the linearly operated cylinder and rotary cylinder for interconnection therebetween;

wherein the BIW is transferred from one workstation to another in two phases comprising a first phase of propelling the BIW with reference to the lower cross member and with the rotary secondary cylinder mounted over the primary linearly operated cylinder; and a second phase of propelling from front side by the actuation of the rotary secondary cylinder, wherein the primary linearly operated cylinder remains standstill or in stationary condition.

In accordance with the present invention, there is provided a method for transferring a BIW by means of said pneumatic mechanism for transferring body-in-white (BIW), said method comprising the steps of:

(a) a first phase for propelling said BIW with reference to cross member, by means of said linearly operated primary pneumatic cylinder and rotary secondary cylinder, and pushed from the under said BIW;

(b) actuating said bearing mounted trolley structure to be located beneath said BIW by means of said primary cylinder, while keeping said rotary cylinder in a standstill;

(c) actuating said primary cylinder again for returning said bearing mounted trolley structure to the home position thereof by keeping said linearly operated primary cylinder and said rotary secondary cylinder standstill and resting on said chucker plate platform;

(d) propelling the front side of said BIW by actuating said swing rod attached to the front end of said rotary secondary cylinder and keeping said linearly operated primary cylinder standstill;

(e) actuating said quick exhaust valve by triggering it by means of said limit switch to overcome the friction to propel said BIW by a distance double the pneumatic cylinder stroke; and

(f) bringing said BIW transfer mechanism in home position by means of said linearly operated primary cylinder for repeating the next BIW transfer cycle.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

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

Figure 1 shows the schematic circuit diagram of the first embodiment of the pneumatic mechanism configured in accordance with the present invention.

Figure 2 shows the schematic circuit diagram of the second embodiment of the pneumatic mechanism configured in accordance with the present invention.

Figure 3 shows the schematic diagram of the first phase of operation of the pneumatic mechanism configured in accordance with the invention.

Figure 4a shows in the first phase of operation of the pneumatic mechanism configured in accordance with the invention.

Figure 4b shows after completion of BIW travel, in which the bearing mounted structure is brought to its home position by actuating the primary cylinder.

Figure 4c shows the positioning of the linearly operating cylinder with respect to the lower portion of BIW, which is taken as the reference point for initiation of BIW displacement.

Figure 4d shows the actuation of the primary cylinder to bring back the bearing trolley mounted structure to its home position.

Figure 5 shows the perspective representation of the second phase of operation of the pneumatic mechanism configured in accordance with the invention.

Figure 6a shows the second phase, in which the third rotary cylinder is actuated to propel BIW front end side with help of a swing rod attached to its extreme end after completion of the first phase.

Figure 6b shows the use of meter in circuit to qualitatively quantify the volumetric delivery.

Figure 7a shows a perspective view of the mechanical construction of the pneumatic mechanism according to the present invention.

Figure 7b shows another perspective view of the mechanical construction of the pneumatic mechanism according to the present invention.

Figure 8a shows a side view of the pneumatic mechanism of Figures 7a-b.

Figure 8b shows a perspective view of the pneumatic mechanism 100 of Figure 8a during the actuation of the rotary cylinder.

Figure 9a shows a front view of the pneumatic mechanism of the Figs. 7a-b.

Figure 9b shows a top view of the pneumatic mechanism of the Figs. 7a-b.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, 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 the schematic circuit diagram of the first embodiment of the pneumatic mechanism 100 configured in accordance with the present invention. This pneumatic mechanism comprises two pneumatic cylinders, i.e. a linearly moveable primary cylinder 102 and a rotary secondary cylinder 104. These cylinders 102, 104 are connected such that the rotary cylinder 104 is mounted over the yoke at the shaft end of primary cylinder 102. The operation of both cylinders 102, 104 is routed through two interconnected pilot valves 106, 108 governed through manual 110 or normal 112 and fail\safe pilot actions 114, 116 respectively, which in turn actuate and deactivate the working of this pneumatic mechanism 100. A quick exhaust valve 118 is installed on the mounting points of the end of primary cylinder 102 and a large flow control valve 120 is deployed to regulate the air flow rate. The first pilot valve 106 is a 5/2-way valve supplied with compressed air at 6-bar pressure, one way of which is connected via the flow control valve 120 to the primary cylinder 102. The second pilot valve 108 has a normal pilot mode 112 and fail/safe mode 116 respectively at either ends thereof. It is also a 5/2-way valve supplied with compressed air at 6-bar pressure, one way each of which is connected to the input and output of primary cylinder 102.

Figure 2 shows the schematic circuit diagram of the second embodiment of the pneumatic mechanism 200 configured in accordance with the present invention, in which the primary cylinder 202 is connected to a first 5/2-way valve 206 supplied with compressed air at 6-bar pressure. The secondary 5/2-way valve 208 is connected to the output and input of the primary valve 206 via a respective AND-gate 230, 240, both of which are similarly supplied with compressed air at 6-bar pressure. These 5/2-way valves 206, 208 are governed through manual 210, 212 pilot actions respectively. Accordingly, both circuit diagrams depict the pneumatic mechanisms 100, 200 installed with fail/safe protocols to trigger the operation of the standstill condition, if system override function is executed. The pneumatic mechanism configured in accordance with the present invention displaces the BIW from one workstation to another by a single lever push. The complete operation is captured in two phases in which linear and rotary cylinders are used in combination to propel the BIW from one workstation to another.
Figure 3 shows the perspective representation of the first phase of operation of the pneumatic mechanisms 100, 200 configured in accordance with the invention. Here, the BIW is propelled from the lower cross member reference with linear cylinder mounted over the primary cylinder.

Figure 4a shows in the first phase of operation of the pneumatic mechanism 100, 200 configured in accordance with the invention. The BIW is pushed from the underbody area of the assembly by using a primary and another secondary cylinder, both these cylinders used in this phase operate linearly and a displacement of 1.5 m is achieved in this first phase. The first stroke linear cylinder is actuated from down side of the BIW and displaces the BIW with reference to the lower cross member in this first phase. During this operation, the rotary cylinder remains standstill. The bearing mounted structure consisting of two cylinders is actuated by the primary cylinder which in turn locates this bearing mounted structure under the BIW.

Figure 4b shows the position after completion of BIW travel of about 1.5 m, in which the bearing mounted structure is brought to its home position by actuating the primary cylinder. In this condition, both actuation cylinders i.e. linearly operating cylinder and the rotary cylinder, are standstill and rest on the chucker plate platform.

Figure 4c shows the positioning of the linearly operating cylinder with respect to the lower portion of BIW, which is taken as the reference point for initiation of the BIW displacement. The front portion of BIW is used to propel it further to another position and in this condition the linear cylinder is standstill. The rotary cylinder is actuated by a lever valve. In turn, the rotary cylinder shaft is connected to the impact bar by means of an Allan bolt used for pushing the reference in the second phase of BIW displacement.

Figure 4d shows the actuation of the primary cylinder to bring back the bearing trolley mounted structure to its home position by the actuation of the primary cylinder and the cycle repeats for next sequence of operation.

Figure 5 shows the perspective representation of the second phase of operation of the pneumatic mechanisms 100, 200 configured in accordance with the invention. Here, the BIW is propelled from the front side with rotary cylinder actuation, in which the first cylinder remains standstill.

Figure 6a shows the second phase, in which the third rotary cylinder is actuated to propel the BIW front end side with the help of a swing rod attached to its extreme end after completion of the first phase. In this second phase, the quick exhaust valve 118 is activated by triggering the limit switch incorporated in this phase. This facilitates in overcoming the coefficient of friction by virtue of Newton’s 2nd Law, wherein due to the acceleration and lumped mass vector, the required force is minimized and thus the BIW is propelled or displaced by double the stroke of the pneumatic cylinder. The figure also shows the use of meter in circuit to qualitatively quantify the volumetric delivery, which in turn creates a pressure-difference within the mechanism for allowing to immediately exhaust any air entrapped within the circuit and thus to integrate the sudden acceleration.

Figure 6b shows using the front portion of the BIW to propel it further to another position and in this condition the linear cylinder is standstill. Rotary cylinder is actuated by lever valve and the rotary cylinder shaft is in turn connected to the impact bar by means of an Allan bolt. The impact bar is used for pushing reference in the second phase of the BIW propulsion. The home position is brought by actuating the primary cylinder again and the cycle repeats for next sequence of operation. Hence, the complete operation is captured in two phases in which the linearly operating cylinders and rotary cylinder are used in combination to propel the BIW from one workstation to another.

Figure 7a shows a perspective view of the mechanical construction of the pneumatic mechanism 100 configured in accordance with the present invention. It consists of a linearly operated pneumatic cylinder 102 with a mounting plate 122 for mounting thereof; a rotary pneumatic cylinder 104 mounted on a mounting plate 142 and having an extended shaft end fitted with an impact bar 126 by means of a mounting bolt 124; a connecting yoke 128 fitted on an end plate 132, an end plate connector 134, bearings 136 fitted on a bearing spindle 138 and fitted under said mounting plate 142.

Figure 7b shows another perspective view of the mechanical construction of the pneumatic mechanism 100 configured in accordance with the present invention.

Figure 8a shows a side view of the pneumatic mechanism 100 of Figs. 7a-b.

Figure 8b shows a perspective view of the pneumatic mechanism 100 of Figure 8a during the actuation of the rotary cylinder.

Figure 9a shows a front view of the pneumatic mechanism 100 of Figs. 7a-b.

Figure 9b shows a top view of the pneumatic mechanism 100 of Figs. 7a-b.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The vehicle cabin mounting system configured in accordance with the present invention has the following technical and economic advantages:

• Provides a safer cabin for cabin occupants.

• Less damage in case of frontal or offset collision of vehicle.

• Light-weight cabin offers a cost advantage.

• Light-weight cabin facilitates more payload to be loaded.

It is to be understood that the present invention is not limited in its application to the details of the construction and to the arrangements of the components as mentioned in the above description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, the terminologies used herein are for the purpose of description and should not be regarded as limiting.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept.

Therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. 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 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. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Therefore, while the embodiments herein have been described in terms of preferred embodiments, the skilled person will recognize that the embodiments herein can be practiced with modification within the spirit and scope of embodiments described herein.

The skilled person can easily make innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies, assemblies and in terms of the size, shapes, orientations and interrelationships without departing from the scope and spirit of the present invention.

The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

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. ,CLAIMS:We claim:

1. A pneumatic mechanism (100, 200) for transferring body-in-white (BIW) between workstations in an automobile manufacturing plant, said BIW transfer mechanism (100, 200) comprising:

• a plurality of pneumatic cylinders for carrying out a dual phase operation to optimally transfer the BIW from one workstation to another;

• at least one quick exhaust valve provided for said pneumatic cylinder;

• a source to supply compressed air to operate said pneumatic cylinders;

• at least one flow control valve to regulate compressed air flow to each of said pneumatic cylinders; and

• a plurality of pilot valves;

wherein the operation of said pneumatic Body-In-White (BIW) transfer mechanism is governed by manual and fail/safe pilot actions performed by said pilot valves to activate or deactivate said pneumatic BIW transfer mechanism.

2. BIW transfer mechanism (100) as claimed in claim 1, wherein said plurality of pneumatic cylinders comprises a primary actuation cylinder (102) for a first traverse and a rotating secondary cylinder (104) for second traverse, said primary and rotary cylinders mounted over BIW trolley in back to back pattern and said trolley mounted over bearing wheels.

3. BIW transfer mechanism (100) as claimed in claim 2, wherein said primary cylinder (102) is a linearly operated and said secondary cylinder (104) is a rotary cylinder actuated by a lever valve.

4. BIW transfer mechanism (100) as claimed in claim 3, wherein said rotary cylinder (104) is mounted over the yoke of said primary cylinder (102) and the operation of both said cylinders (102, 104) is routed through two of said pilot valves (106, 108) interconnected and governed through manual and fail/safe actions (114, 116) to activate or deactivate said BIW transfer mechanism (100).
5. BIW transfer mechanism (100) as claimed in claim 2, wherein said quick exhaust valve (118) is installed at the mounting point of said primary cylinder (102) end and said flow control valve (120) is provided to regulate the flow rate of compressed air.

6. BIW transfer mechanism (100, 200) as claimed in claim 1, wherein said mechanism is installed with fail/safe pilot protocols to trigger the operation of said BIW transfer mechanism to standstill condition, when the override function of said BIW transfer mechanism is executed.

7. BIW transfer mechanism (100) as claimed in claim 3, wherein said rotary secondary cylinder (104) is connected to an impact bar used for pushing said BIW during the second phase of transfer thereof from one workstation to another.

8. BIW transfer mechanism (100) as claimed in claim 1, wherein said BIW is propelled with reference to the cross member in the first phase and pushed from the under said BIW by using said linearly operated primary cylinder (102) and rotary secondary cylinder (104); and said rotary cylinder (104) is in a standstill position.

9. BIW transfer mechanism (100) as claimed in claim 8, wherein a bearing trolley mounted structure is provided having two cylinders actuated by means of said primary cylinder (102) for locating said bearing mounted structure under said BIW.

10. BIW transfer mechanism (100) as claimed in claim 9, wherein said primary cylinder (102) is actuated to bring home said bearing trolley mounted structure; and said linearly operated primary cylinder (102) and rotary secondary cylinder (104) is in standstill position and rests on a chucker plate platform.

11. BIW transfer mechanism (100) as claimed in claim 1, wherein the front side of said BIW is propelled by actuating the swing rod attached at the front end of said rotary cylinder (104) and a limit switch triggers said quick exhaust valve (118) to move said BIW in this second phase.

12. BIW transfer mechanism (100) as claimed in claim 11, wherein said linearly operated cylinder (102) is in standstill position and said rotary cylinder (104) is actuated by rotating a lever valve connected to an impact bar to push said BIW in its final position and said primary cylinder (102) is actuated to bring it in home position.

13. BIW transfer mechanism (100, 200) as claimed in claim 1, wherein said mechanism comprises:

• a principal cylinder having the largest stroke length;

• at least one linearly operated pneumatic cylinder (102); preferably a primary and a secondary pneumatic cylinder each;

• a rotary pneumatic cylinder (104) having an extended shaft end (106);

• an L-type mounting plate (142) for mounting both said linearly operated cylinder (102) and said rotary cylinder (104);

• said rotary cylinder mounted on said L-type mounting plate (142) supported on bearings (136) fitted on a bearing spindle (138);

• an impact bar (126) mounted on said extended shaft end (106) by means of a mounting bolt (124); and

• an end plate connector (134) on said L-type mounting plate (142) and disposed between said linearly operated cylinder (102) and rotary cylinder (104) for interconnection therebetween;

wherein said BIW is transferred from one workstation to another in two phases comprising a first phase of propelling said BIW with reference to said lower cross member and with said rotary secondary cylinder (104) mounted over said primary linearly operated cylinder (102); and a second phase of propelling from front side by the actuation of said rotary secondary cylinder (104), wherein said primary linearly operated cylinder (102) remains standstill or in stationary condition.

14. A method for transferring a BIW by means of the pneumatic mechanism (100, 200) for transferring body-in-white (BIW) as claimed in anyone of the claims 1 to 13, said method comprising the steps of:

(a) a first phase for propelling said BIW with reference to cross member, by means of said linearly operated primary pneumatic cylinder (102) and rotary secondary cylinder (104), and pushed from the under said BIW;

(b) actuating said bearing mounted trolley structure to be located beneath said BIW by means of said primary cylinder (102), while keeping said rotary cylinder (104) in a standstill;

(c) actuating said primary cylinder (102) again for returning said bearing mounted trolley structure to the home position thereof by keeping said linearly operated primary cylinder (102) and said rotary secondary cylinder (104) standstill and resting on said chucker plate platform;

(d) propelling the front side of said BIW by actuating said swing rod attached to the front end of said rotary secondary cylinder (104) and keeping said linearly operated primary cylinder (102) standstill;

(e) actuating said quick exhaust valve by triggering it by means of said limit switch to overcome the friction to propel said BIW by a distance double the pneumatic cylinder stroke; and

(f) bringing said BIW transfer mechanism in home position by means of said linearly operated primary cylinder (102) for repeating the next BIW transfer cycle.

Digitally Signed.

Dated: this 18th day of December 2017. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT