Claims:We claim:

1. A mechanism for safe movement of body-in-white carried mounted on a transfer car, the mechanism comprising the following:

a) a holding frame assembly mounted on the transfer car by means of a plurality of sets of fasteners assembly;

b) a pendulum lever assembly pivotably mounted on the holding frame assembly;

c) a body-in-white (BIW) holding fixture mounted on transfer car for carrying a BIW; and

d) a fixed-base lever assembly mounted on a power roller bed

wherein the transfer car is equipped with a first proximity sensor at the receiving end thereof for commencing movement of the BIW carrying holding fixture from the receiving end and a second proximity sensor at the delivery end thereof first to reduce the rotational speed and subsequently to stop the roller motor at the delivery end thereof for stopping the forward movement of the BIW carrying holding fixture on reaching the delivery end and a third positional proximity sensor mounted on the transfer car.

2. Mechanism as claimed in claim 1, wherein the holding frame assembly comprises:

• a pair of mutually parallel vertical steel plates; the vertical plates joined to a base plate perpendicular thereto; and a stopper plate disposed between the two vertical plates;

• the vertical plates having a pivot hole each provided adjacent the end thereof away from the base plate for pivoting the pendulum lever assembly on the holding frame assembly;

• the base plate having a plurality of holes for mounting the pendulum lever assembly along with the holding frame assembly on the transfer car at the delivery end thereof by tightening a respective fastener therein; the pendulum lever assembly pivoted about a pivot bolt fixed between the two vertical plates and passing through the pivot holes;

wherein the stopper plate is welded parallel to the base plate and disposed between the vertical plates and in a vertical plane passing between the pivot holes and base plate for restricting the all-round (3600) rotation of the pendulum lever about the pivot bolt of the vertical steel plates for providing a vertical locking position thereof.

3. Mechanism as claimed in claim 1, wherein the pendulum lever assembly comprising:

• a vertical pendulum lever body provided with a pivot bolt passing through a pivot hole in a plane transverse to the transfer car;

• a profiled pendulum lever laterally connected to the pendulum body on one side thereof; and

• a balancing weight laterally attached to the pendulum body on the other side thereof for keeping the pendulum lever assembly in a stable vertical position in a locked position thereof;

wherein a reinforcement plate is attached at the top of the pendulum lever body side facing the delivery end of the transfer car mounted with the body-in-white (BIW) holding fixture; the pendulum lever body being pivotable about the pivot bolt thereof.

4. Mechanism as claimed in claim 3, wherein the pendulum lever is configured of a bent metallic rod to provide a pivoting motion to the pendulum lever assembly on coming in contact with the receiving end of the power roller bed, by rotation about the pivot bolt thereof.

5. Mechanism as claimed in claim 1, wherein the fixed-base lever assembly comprises:

• a vertical mounting plate for mounting the fixed-base lever assembly by means of a plurality of sets of fasteners; and
• a vertical fixed lever plate welded to the mounting plate by means of a right-angled bracket;

wherein the vertical fixed lever plate contacts the vertically locked pendulum lever by coming in contact with the forward moving BIW holding fixture of the transfer car and to rotate the pendulum lever about the pivot bolt thereof for unlocking from the vertical position thereof for facilitating the forward movement of the BIW holding fixture to deliver the BIW on the power roller bed.

6. Mechanism as claimed in claim 1, wherein the balancing weight is configured to bring the pendulum lever assembly again in the vertical position thereof by a counter rotation of the pendulum lever assembly about the pivot bolt thereof, on a rearward movement of the empty BIW holding fixture towards the receiving end of the transfer car.

7. Mechanism as claimed in claim 1, wherein the first proximity sensor gets activated with the BIW holding fixture entering from the receiving end of the transfer car and signal is issued to the controller for starting the transfer car roller motor for a forward movement of the BIW holding fixture mounted on the transfer car toward the delivery end thereof.

8. Mechanism as claimed in claim 1, wherein with the BIW holding fixture approaching the delivery end of the transfer car, the second proximity sensor gets activated to reduce the rotational speed of the roller motor of the transfer car and a signal is issued to the controller for completely stopping the transfer car roller motor for stopping the forward movement of the BIW holding fixture mounted on the transfer car and to restart the roller motor to move the transfer car with the BIW holding fixture toward the delivery end thereof.

9. Mechanism as claimed in claim 1, wherein with the transfer car mounted with the BIW holding fixture reaches the delivery destination, third proximity sensor gets activated to stop the forward movement of the transfer car to deliver the BIW at the delivery destination on the power roller bed and to return to the home position thereof.

10. A method for safe movement of body-in-white carried mounted on a transfer car by the mechanism as claimed in anyone of the claims 1 to 9, the method comprising the steps of:

• entering the BIW holding fixture mounted on the transfer car from the receiving end thereof;

• actuating the first proximity sensor for communicating to the controller to start operation of the roller motor of the transfer car;

• moving the BIW holding fixture from the receiving end to the delivery end of the transfer car;

• actuating the second proximity sensor with the BIW holding fixture approaching the delivery end of the transfer car, for communicating to the controller to slow down the rotation of the roller motor;

• completely stopping the roller motor operation to apply brakes to stop the forward movement of the BIW holding fixture;

• starting the forward movement of the transfer car mounted with the BIW holding fixture to deliver the BIW at the delivery destination thereof on the power roller bed;

• actuating the third positional proximity sensor mounted on the transfer car to stop the roller motor to stop the forward movement of the transfer car mounted with the BIW holding fixture on reaching the delivery destination thereof on the power roller bed;

• delivering the BIW at the destination thereof on the power roller bed; and

• returning the transfer car with the empty holding fixture to the home position thereof.

Dated: this day of 31st December, 2016. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT , Description:FIELD OF INVENTION

The present invention relates to mechanism for moving heavy components and sub-assemblies in the manufacturing plants. In particular, the present invention relates to transfer car mechanism used in an automobile manufacturing plant. More particularly, the present invention relates to the automobile transfer mechanism for protecting the body-in-white (BIW) from falling from the transfer car in an automobile manufacturing plant.

BACKGROUND OF THE INVENTION

The transfer car is a conveyor which installed on or below the floor level. Like overhead conveyors, the transfer cars basically comprise of chain, track, drive unit, take up unit and oiler. Pegs, fixtures, trolleys, pallets to support the component are generally required depending on the type of component and conveyor selected for the said application. The transfer cars are generally custom built depending on the type of component to be handled as well as the application, process requirement.

In automobile industry transfer cars are widely used in Body shops, Paint shops and TCF’s (Trim, Chassis & final assembly) to transfer BIW’s (Body in white), painted bodies and vehicles from one station to another station for next operation as per process requirement. Transfer cars are equipped with VFD electric motors, Speed control proximity sensors, Position confirmation proximity sensor, Break system and other mechanical drive systems. All entire things are connected through PLC to operated and control the transfer systems as per process requirement.

In weld/body shop for BIW movement different types of material handling equipment’s are used, e.g.

i) Straight travel transfer cars,

ii) Cross travel transfer cars and

iii) Turn tables.
On each transfer car/turn table three proximity sensors are fitted. First proximity sensor is fitted at the receiving end of transfer car/turn table who’s on signal start roller motor to pull BIW along with its holding fixture. Second proximity sensor is fitted near to the delivery end of transfer car/turn table who’s on signal reduce the roller motor speed through VFD and the third proximity sensor is fitted at the end of transfer car/turn table to stop the roller motor.

Then transfer car/turn table moves along with BIW and its holding fixture to the next location where it should be delivered. After delivering BIW & its holding fixture transfer car/turn table moves to its home position.

There are three incidences where this defined process of transfer car/ turntable was not followed due to electrical circuit malfunctioning. In this case, the electrical contact was stuck and the roller motor could not be stopped due to a continuous power supply. Because of this electrical circuit malfunction, the BIW along with its holding fixture had an overtravel and fell down on the shop floor before reaching its destination.

Such incidents have a risk of occurrence of major injury to human beings, in case of involvement of a human interface. This meant that whatsoever basic electrical safety systems were provided by the Original Equipment Manufacturer (OEM) were not sufficient and therefore, there is an existing need for a mechanical safety system as well.

In public domain, there are few safety means/ guards available for turn tables and cross travel type transfer cars to overcome over travel and fall down issue in case of electrical circuit failure.

But none of these prior safety means/ guards describe and teaches the solution for stopping BIW and its holding fixture forward movement in case of electrical circuit failure for straight travel transfer cars, and thereby preventing major accident. Therefore, the present invention is done to stop over travel of BIW along with its holding fixture in case of electrical circuit failure and prevent the huge potential major accident and huge production loss.
PRIOR ART

US 2919657 A discloses in combination with a transfer car having a flat horizontal bed and movable in a straight path, a pair of stationary track rails located perpendicular to the path of the transfer car, a pair of transversely disposed rail balls upon the bed of the transfer car adapted to register with the ball of said stationary track rails having spaced acute angular ends substantially parallel to each other, acute angular rail lock blocks mounted slidable upon the bed of the transfer car and shaped to fit between said angular ends, and means for moving said rail lock blocks into position between the angular ends of the transversely disposed rail balls and the balls of said stationary track rails, so that each rail lock block is supported partially upon the bed of the transfer car and partially upon the top of the web of the corresponding track rail, said rail lock blocks holding the transfer car against movement when they are located between the angular ends of the rails.

CN 203714685 U discloses a car body in white production line fully-automatic conveying device. The car body in white production line fully-automatic conveying device comprises a gripper support rack, a chuck cylinder, a guide plate, a travel switch, a chuck, a vertical moving rail, a vertical moving rack, a first guide wheel set, a bottom plate, a second guide wheel set, a cross beam, a horizontal drag chain, a vertical motor set, a stand column, a clamping block, a horizontal motor set, a third guide wheel set, a vertical drag chain, a fourth guide wheel set, an overload protecting device, a fifth guide wheel set, a horizontal rail and a horizontal moving rack. The car body in white production line fully-automatic conveying device achieves automatic transportation of workpieces among multiple stations in a pneumatic and electric combined mode; every transmission motor is controlled through a frequency converter to set the speed of every part as required; every brake point is provided with a reduction sensor to ensure the operating stability of the integral device; the clamp of the conveying device is operated by controlling air cylinders through electromagnetic valves and has an automatic holding function in a power-off or air cut-off state, so that the operation of the integral device can be safer and more reliable.

JP H03 (1991) 137363 A discloses a car incoming and outgoing device is equipped with a primary transport element for protrusive mounting of a comb-shaped placing piece, on which a car is placed through tire, and a secondary side transport element with another placing piece installed protruding, and the primary side transport element is overlapped below the secondary one. The placing piece on the primary side is installed with possibility of converging in the condition that it is above overlapped with the secondary side placing piece. With a converging station, the two pieces are so installed that it is possible to rise and fall while submerging up and down relatively. This ensures safe and certain transfer with simple manipulation.

KR 20040059213 A discloses an apparatus for automatically detecting position of wheels for sintering transfer car is provided in which an operator directly measures displacement of a plurality of wheels of the transfer car safely and accurately by detecting displacement and separation of the wheels using a probe and simultaneously recording the measured data. The apparatus comprises a probe installed in such a way that the probe is elastically contacted with the side of the wheels for the sintering transfer car to convert the detected displacement values into straight momentum by detecting displacement values according to movement of the wheels for the sintering transfer car and running rails; a recording part connected with the probe to record the straight momentum converted in the probe on a recording paper; and a power transmission part for transmitting power for interlocking the recording part according to the straight momentum of the probe, wherein the recording part comprises a data conversion means for converting the straight momentum of the probe into digital data recognized by computer so that the straight momentum of the probe is transmitted to the computer through the data conversion means, wherein the power transmission part comprises upper block and lower block capable of rotating the probe to prevent damage of the probe due to interference of the wheels for the sintering transfer car and the probe; and tension spring and stopper for vertically returning the probe to the surface of the wheels for the sintering transfer car, and wherein the power transmission part comprises touch bar and limit switch capable of starting and stopping motor according to movement of the probe.
DISADVANTAGES WITH THE PRIOR ART

However, the problems with the conventional mechanism for protecting body-in-white (BIW) from falling from the transfer car are briefly discussed below:

• Mostly require external energy to operate transfer mechanism system.
• Require more space.
• Difficult to install, operate and maintain.
• High manufacturing cost due to loss of production.
• Unsafe during transfer of the BIW from the transfer car in case of an electrical circuit failure due to overtravel of BIW.
• Higher system restoration time in case of an electrical circuit failure.
• Prevents accidents.
• Higher loss due to damaged BIWs as fall down from the transfer cars.

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 stop over travel of BIW along with its holding fixture in case of electric circuit failure to eliminate very high potential major accident.

Another object of the present invention is to prevent heavy production loss due to high restoration time.

Still another object of the present invention is to prevent scrap cost of BIW and its holding fixture which get damage due to fall down on floor.

Yet another object of the present invention is to prevent use of any kind of external energy to operate entire mechanical safety system.

A further object of the present invention is to provide a compact and easy to maintain mechanical safety system on all type of transfer cars/ turn tables and is easy to mount thereon.
A still further object of the present invention is to provide a mechanical safety system with low cost and easy to manufacture.

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

Accordingly, the mechanism to arrest the movement of Body-in-white (BIW) in the transfer case configured in accordance with the present invention can be used worldwide in material handling equipment, e.g. in transfer car, turn table used for transferring different types of components and/or sub-assemblies as well as in applications and processes requiring no use of any external energy. It is based on a see-saw mechanism provided with a balancing weight to cater the issue of overtravel and falling down of pegs, fixtures, trolleys, pallets which must be used for supporting the component to be transferred from one location to another location for further operations as per the process requirements.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a mechanism for safe movement of body-in-white carried mounted on a transfer car, the mechanism comprising the following:

a) a holding frame assembly mounted on the transfer car by means of a plurality of sets of fasteners assembly;

b) a pendulum lever assembly pivotably mounted on the holding frame assembly;

c) a body-in-white (BIW) holding fixture mounted on transfer car for carrying a BIW; and

d) a fixed-base lever assembly mounted on a power roller bed

wherein the transfer car is equipped with a first proximity sensor at the receiving end thereof for commencing movement of the BIW carrying holding fixture from the receiving end and a second proximity sensor at the delivery end thereof first to reduce the rotational speed and subsequently to stop the roller motor at the delivery end thereof for stopping the forward movement of the BIW carrying holding fixture on reaching the delivery end and a third positional proximity sensor mounted on the transfer car.

In one embodiment of the present invention, the holding frame assembly comprises:

• a pair of mutually parallel vertical steel plates; the vertical plates joined to a base plate perpendicular thereto; and a stopper plate disposed between the two vertical plates;

• the vertical plates having a pivot hole each provided adjacent the end thereof away from the base plate for pivoting the pendulum lever assembly on the holding frame assembly;

• the base plate having a plurality of holes for mounting the pendulum lever assembly along with the holding frame assembly on the transfer car at the delivery end thereof by tightening a respective fastener therein; the pendulum lever assembly pivoted about a pivot bolt fixed between the two vertical plates and passing through the pivot holes;

wherein the stopper plate is welded parallel to the base plate and disposed between the vertical plates and in a vertical plane passing between the pivot holes and base plate for restricting the all-round (3600) rotation of the pendulum lever about the pivot bolt of the vertical steel plates for providing a vertical locking position thereof.

In another embodiment of the present invention, the pendulum lever assembly comprising:

• a vertical pendulum lever body provided with a pivot bolt passing through a pivot hole in a plane transverse to the transfer car;

• a profiled pendulum lever laterally connected to the pendulum body on one side thereof; and

• a balancing weight laterally attached to the pendulum body on the other side thereof for keeping the pendulum lever assembly in a stable vertical position in a locked position thereof;

wherein a reinforcement plate is attached at the top of the pendulum lever body side facing the delivery end of the transfer car mounted with the body-in-white (BIW) holding fixture; the pendulum lever body being pivotable about the pivot bolt thereof.

In still another embodiment of the present invention, the pendulum lever is configured of a bent metallic rod to provide a pivoting motion to the pendulum lever assembly on coming in contact with the receiving end of the power roller bed, by rotation about the pivot bolt thereof.

In yet another embodiment of the present invention, the fixed-base lever assembly comprises:

• a vertical mounting plate for mounting the fixed-base lever assembly by means of a plurality of sets of fasteners; and
• a vertical fixed lever plate welded to the mounting plate by means of a right-angled bracket;

wherein the vertical fixed lever plate contacts the vertically locked pendulum lever by coming in contact with the forward moving BIW holding fixture of the transfer car and to rotate the pendulum lever about the pivot bolt thereof for unlocking from the vertical position thereof for facilitating the forward movement of the BIW holding fixture to deliver the BIW on the power roller bed.

In a further embodiment of the present invention, the balancing weight is configured to bring the pendulum lever assembly again in the vertical position thereof by a counter rotation of the pendulum lever assembly about the pivot bolt thereof, on a rearward movement of the empty BIW holding fixture towards the receiving end of the transfer car.
In a still further embodiment of the present invention, the first proximity sensor gets activated with the BIW holding fixture entering from the receiving end of the transfer car and signal is issued to the controller for starting the transfer car roller motor for a forward movement of the BIW holding fixture mounted on the transfer car toward the delivery end thereof.

In a yet further embodiment of the present invention, with the BIW holding fixture approaching the delivery end of the transfer car, the second proximity sensor gets activated to reduce the rotational speed of the roller motor of the transfer car and a signal is issued to the controller for completely stopping the transfer car roller motor for stopping the forward movement of the BIW holding fixture mounted on the transfer car and to restart the roller motor to move the transfer car with the BIW holding fixture toward the delivery end thereof.

In one more embodiment of the present invention, with the transfer car mounted with the BIW holding fixture reaches the delivery destination, third proximity sensor gets activated to stop the forward movement of the transfer car to deliver the BIW at the delivery destination on the power roller bed and to return to the home position thereof.

In accordance with the present invention, there is also provided a method for safe movement of body-in-white carried mounted on a transfer car by the mechanism mounted on a transfer car, the method comprises the steps of:

• entering the BIW holding fixture mounted on the transfer car from the receiving end thereof;

• actuating the first proximity sensor for communicating to the controller to start operation of the roller motor of the transfer car;

• moving the BIW holding fixture from the receiving end to the delivery end of the transfer car;

• actuating the second proximity sensor with the BIW holding fixture approaching the delivery end of the transfer car, for communicating to the controller to slow down the rotation of the roller motor;
• completely stopping the roller motor operation to apply brakes to stop the forward movement of the BIW holding fixture;

• starting the forward movement of the transfer car mounted with the BIW holding fixture to deliver the BIW at the delivery destination thereof on the power roller bed;

• actuating the third positional proximity sensor mounted on the transfer car to stop the roller motor to stop the forward movement of the transfer car mounted with the BIW holding fixture on reaching the delivery destination thereof on the power roller bed;

• delivering the BIW at the destination thereof on the power roller bed; and

• returning the transfer car with the empty holding fixture to the home position thereof.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings.

Figure 1 shows the exploded view of the mechanical safety system configured in accordance with the present invention.

Figure 2 shows the detail perspective view of the holding frame of the mechanical safety system configured in accordance with the present invention.

Figure 3 shows the detail perspective view of the pendulum lever of the mechanical safety system.

Figure 4 shows a detail perspective view of the main sub-assemblies of the mechanical safety system of Figure 1.

Figure 5a shows detailed side view of the mechanical safety system assembled on the transfer car and the power roller bed. The encircled portion A is explained in further details in Figure 5b.
Figure 5b shows an enlarged view of the encircled portion A of Figure 5a.

Figure 6a shows a perspective view of the mechanical safety system in a locked position and with the BIW holding fixture details as provided on the transfer car.

Figure 6b shows a perspective view of the mechanical safety system in an unlocked position with BIW holding fixture on transfer car and power roller bed.

Figure 6c shows a detailed perspective view of the assembly of the mechanical safety system in an unlocked position and the BIW holding fixture moving forward from the transfer car towards the power roller bed.

Figure 6d shows a detailed perspective view of the mechanical safety system in an unlocked position with the BIW holding fixture fitted on the transfer car.

Figure 6e shows an enlarged perspective view of the mechanical safety system assembly retaining the locked position thereof, after breaking contact of the transfer car from the power roller bed.

DETALED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention provides a fail-proof mechanical safety system for transfer cars to avoid falling down of the BIW along with the holding fixture from the transfer car carrying the same, due to any electrical circuit failure or malfunction. The scope of present invention is not limited to the transfer car travelling in a straight direction and it can also be implemented on cross-travel transfer cars as well as on turn tables.

Figure 1 shows the exploded view of the mechanical safety system 100 configured in accordance with the present invention. It is compact and easy to be mounted in either straight or cross-travel transfer cars as well as in turn tables. This present invention comprises of three sub-assemblies, i.e. a holding frame 10, a pendulum lever 50 assembly and a fixed base lever 70 assembled together to form the overall mechanical safety system 100 for arresting the movement of a Body-in-white (BIW) loaded in a transfer car 80. The other important components of this system 100 are: a fixed base power roller bed 30, a fixed base lever 70 (both not shown here), a hexagonal head pivot bolt 60, thrust washers 66, plain washers 76, Nylock nut 62 for locking the pivot bolt 60 and the set of cap screws 72, spring washers 74, frame locking nut 78 are the other auxiliary components thereof.

Figure 2 shows the detail perspective view of the holding frame 10 of the mechanical safety system 100 configured in accordance with the present invention. The holding frame 10 has a unique shape constituting the basic element of the invention, which comprises total four mild steel plates 12, 16, 22, the size and thickness of which varies as per the requirement. This unique shape involves two vertical parallel plates 12 with a hole 14 each for welding the pivot pin to base plate 16 having four mounting holes 18 at four corners thereof. The opening between these two vertical plates 12 equals the width of the pendulum lever 50 including the thickness of two thrust washers on either side thereof. The vertical plates 12 are welded with due care after a proper weld preparation to avoid a weak joint. A 45°x 50 mm chamfer 20 is provided on the vertical plates 12, which is required to facilitate the rotational movement of the balancing weight 30 and the fixed base lever 70 for operating the pendulum lever 50, both of which are mounted on the pendulum lever 50. An anti-rotation pendulum lever stopper 22 is welded between the two vertical plates 12 to restrict a 360° rotation of the pendulum lever 50 and to provide a rotation only in a controlled area. Therefore, this anti-rotation pendulum lever stopper 22 provides a locking position for the pendulum lever 50. The length of the vertical plates 12 varies as per the minimum gap or opening available between the transfer car to the next transfer element thereof and it can be mounted on any moving or stationary transfer car or transfer element by changing the center distance of the mounting holes 14.

Figure 3 shows the detail perspective view of the pendulum lever assembly 50 of the mechanical safety system 100. The pendulum lever assembly 50 is fitted between two vertical plates 12 of the holding frame 10. The pendulum lever assembly 50 comprises four elements, i.e. a pendulum lever body made of heavy duty mild steel square pipe 52, a dead weight 54, a uniquely designed pendulum lever 56 made of a high strength steel rod and a 5mm thick Mild steel plate as a reinforcement plate 58. This lever 56 is used to convert reciprocating motion of the transfer car 100 for the rotation of the entire pendulum lever assembly 50. At one end of the pendulum lever body 52, a 60° chamfer 64 is provided and the opening thereof is covered with a cover plate (not visible in this figure). This 60° chamfer 64 on the pendulum lever body 52 is provided to avoid the necessity of excess (up to approx. 90°) rotation for creating a clear path for BIW holding fixture 90 without rubbing and interrupting the forward movement thereof, when the pendulum lever assembly 50 is in an unlocked position thereof. This 60° chamfer also plays an important role, because the distance required to operate this entire system is very less (i.e. approximate 250 mm). The main purpose of the dead weight 54 is to keep the pendulum lever assembly 50 always in a locked (vertical) position, when the transfer car position is at the BIW holding fixture 90 receiving end. Also, this dead weight 54 restores the unlocked (horizontal) position of the pendulum lever 50 to the locked (vertical) position thereof, when it not in contact with the fixed base lever 70. On the opposite side of the 60°chamfer 52 of the pendulum lever body 52, an additional reinforcement 58 is provided for avoiding a bending of the pendulum lever body 52 due to the impact of the BIW holding fixture 90 in case of an electrical circuit failure. This pendulum lever body 52 has holes at the center of both the side thereof for inserting a pivot bolt 60.

Figure 4 shows a detailed perspective view of the main sub-assemblies of the mechanical safety system 100 of Figure 1. The mechanical safety system including the pendulum lever assembly 50 is fixed in the holding frame 10 by using a hexagonal head pivot bolt 60 and locked by means of a Nylock nut 62. Here, two oil-free thrust washers 66 are placed between the two sides of the pendulum lever stopper 22 for the vertical plates 20 of the holding frame 10 to avoid a wearing out of the pendulum lever 50 and the holding frame 10 due to continuous rotary movement at every cycle. This entire assembly 100 is then mounted on the delivery end of the transfer car 80 by means of four sets of cap screws 72, spring washer 74, plain washer 76 and locking nut 78. A fixed base lever 70 is mounted at the receiving end of the fixed base of the power roller bed 30 or other fix roller mounted base with the help of another four sets of cap screw 72, spring washer 74, plain washer 76 and frame locking nut 78.

Figure 5a shows detailed side view of the mechanical safety system 100 assembled on the transfer car 80 and the power roller bed 30. The encircled portion A is explained in further details in Figure 5b.

Figure 5b shows an enlarged side view of the encircled portion A of Figure 5a. The fixed lever sub-assembly 40 mounted on power roller bed 30 receiving end. The second sub-assembly of the pendulum lever 50 is mounted at the delivery end of the transfer car 80.

Figure 6a shows a perspective view of the mechanical safety system 100 in a locked position and with the BIW holding fixture details as provided on the transfer car 80. Here, a gap D is provided for rotation R of the pendulum stopper 22 which is in a locked position.

Figure 6b shows a perspective view of the mechanical safety system 100 in an unlocked position on the transfer car 80 with BIW holding fixture 10. The clockwise rotation R of the pendulum lever 56, which is in an unlocked position, allows the movement of the BIW holding fixture. This is due to the fact that the path for moving the BIW holding fixture is now clear for forward movement.

Figure 6c shows a detailed perspective view of the assembly of the mechanical safety system 100 in an unlocked position and the BIW holding fixture 90 moving forward from the transfer car 80 towards the power roller bed 30.

Figure 6d shows a detailed perspective view of the mechanical safety system 100 in an unlocked position with the BIW holding fixture 90 fitted on the transfer car 80 making contact with the power roller bed 30. Here, BIW along with the holding fixture in a forward movement is locked by the pendulum stopper in case of a failure of the electrical circuit or any malfunctioning thereof.

Figure 6e shows an enlarged perspective view of the mechanical safety system assembly 100 retaining the locked position thereof again, after breaking contact of the transfer car 30 from the power roller bed 30 (not shown here).

WORKING OF THE INVENTION

Figures 6a to 6e show the detailed working of the for safe movement of body-in-white carried mounted on a transfer car configured in accordance with the present invention, which is described in the following:

When at the BIW holding-fixture 90 enters from the transfer car 80 receiving end, the proximity sensor present at the receiving end of the transfer car 80 gets activated and issues signal to the programmable logic controller (PLC) to start the roller motor to start the clockwise rotation R thereof (Figure 6a).

With this, the BIW holding fixture 90 starts moving from the receiving end of the transfer car 80 to the delivery end thereof. Before reaching the delivery end, another proximity sensor provided on the transfer car 80 gets activated and issues signal to a variable frequency drive (VFD) motor to reduce the rotational speed through the PLC (Figure 6b).

Once the BIW holding fixture 90 reaches the delivery end of the transfer car 80, the proximity sensor provided on the delivery end of the transfer car 80 gets activated and issues signal to the PLC to stop the motor rotation and applies brakes, so that the forward movement of BIW holding fixture 90 stops. After the motor stops rotating, the transfer car 80 starts to move along with the BIW holding fixture 90 to deliver it to its next destination. After the transfer car 80 reaches its destination, the positional proximity sensor mounted on it 80 gets activated and issues signal to the PLC to stop the forward movement of the transfer car 80 and delivers the BIW holding fixture 90 to the power roller bed 30 and comes back to its home position (Figure 6c).

This is a normal operational cycle of the transfer car 80. In this cycle, the pendulum stopper lever 70 mounted on the transfer car 80 is not in contact with the BIW holding fixture 90. There is a gap present between the BIW holding fixture 90 and the pendulum stopper 10 for easy rotation of the pendulum stopper lever 70 (Figure 6a).

When the transfer car 80 moves along with BIW holding fixture 90 to deliver it to its next destination, i.e. the power roller bed 30, the fixed stopper 70 mounted on the receiving end of the power roller bed 30 comes in contact with the pendulum stopper lever 70 mounted on the delivery end of the transfer car 80. Due to the forward movement of the transfer car 80, the pendulum stopper lever 70 exerts pressure on the fixed base lever 70 mounted on the power roller bed 30. Due to this unique design of the pendulum stopper lever 22, as the transfer car 80 moves forward, the pendulum stopper lever 22 starts to rotate. At the instant, the transfer car 80 reaches its destination, the pendulum stopper 22 rotates completely and clears the path of the BIW holding fixture 90 to move forward on the power roller bed 30 (Figure 6b).

Once the BIW holding fixture 90 is completely transferred from the transfer car 80 to the power roller bed 30, the transfer car 80 starts moving back to its home position. Due to the reverse movement of the transfer car 80 to its home position, the contact of the fixed stopper 75 to the pendulum stopper lever 22 breaks. Once this contact is broken due to the dead weight mounted on the pendulum stopper lever 22, it rotates in an anticlockwise direction and comes to its vertical locking position.

TECHNICAL ADVANTAGES OF THE INVENTION

The mechanism to arrest the movement of Body-in-white (BIW) in the transfer case configured in accordance with the present invention has the following technical and economic advantages:

• Does not use of any kind of external energy to operate entire system.

• Compact in design and easy to install & maintain.

• More reliable as entries system made of high strength mild steel.

• Low manufacturing cost.

• Ensures 100% safe operation while transferring the body-in-white (BIW) from the transfer car, in case of electrical circuit failure.

• Unique solution for transfer cars travelling straight type.
• Not in use in any other industry and not supplied by any OEM.

• 100% elimination of unsafe condition for the operator, which may lead to FATAL accidents.

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

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

The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention. Although, only the preferred embodiments have been described herein, the skilled person in the art would readily recognize to apply these embodiments with any modification possible within the spirit and scope of the present invention as described in this specification.

Therefore, innumerable changes, variations, modifications, alterations may be made and/or integrations in terms of materials and method used may be devised to configure, manufacture and assemble various constituents, components, subassemblies and assemblies according to their size, shapes, orientations and interrelationships.

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

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 experts can optimally modify and use the invention and its different exemplary embodiments with reference to the intended use. In the claims and the description, the terms “containing” and “having” are used as linguistically neutral terminologies for the corresponding terms “comprising”. Furthermore, the use of the term “one” shall not exclude the plurality of such features and components described.