DESC:FIELD OF THE INVENTION

The present invention relates to safety arrangement provided in the vehicle manufacturing plants. In particular, the present invention relates to means for avoiding roll-over of vehicle being lifted from an assembly line using a hoisting mechanism. More particularly, the present invention relates to a safety arrangement for ensuring the accident-free hoisting operation on a vehicle assembly line.

BACKGROUND OF THE INVENTION

Normally, any vehicle manufacturing plant is equipped with lifting arrangement for lifting the under-assembly vehicles from the assembly lines. One of the most common arrangement includes a hoisting mechanism provided over the vehicle assembly line, which can be used for upward movement of the vehicle for lifting and transferring an under-assembly or assembled vehicle from the assembly line by attaching a plurality of fixtures or tackles around different points of the vehicle.

However, it has been experienced that moving the vehicles from the assembly line by using a hoisting mechanism often leads to accidents, particularly due to the reason that at least one of the tackles used for hoisting the vehicle is inadvertently left attached to the vehicle. So, when the hoisting mechanism is lifted without removing any of the tackles that remained attached to the vehicle, the hoist tilts to the side with one of the tackles still remaining attached to the vehicle. Any such lapse on the part of the operator by using the hoist for lifting/lowering and transferring the vehicle has serious consequences, which may cause, not only fatal injuries but also loss of production as well as personnel and material losses.

The vehicle manufacturing facilities of the present applicants have experienced several such fatalities, so it was felt necessary to improve the security of operation of the vehicle hoisting arrangements in their various manufacturing plants spread at different locations.
DISADVANTAGES WITH THE PRIOR ART

In the existing vehicle manufacturing units, there is no safety arrangement which takes care of ensuring the removal of tackles attached to the vehicles being lifted or transferred from one location on the assembly line to another operational area or to the storage area.

The absence of any method or system for ensuring the safety of the personnel and/or equipment involved in hoisting, lifting or transferring the vehicles on using the hoisting mechanisms often leads to serious injuries and loss of properties in the vehicle manufacturing plants. Therefore, an improved safety environment is needed around the lifting/hoisting/transfer arrangement in the assembly line.

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 an improved safety arrangement for ensuring the accident-free hoisting operation on a vehicle assembly line.

Another object of the present invention is to provide a fail-safe safety arrangement for preventing the vehicle falling on the conveyor line during hoisting of the vehicle from the assembly line.

Still another object of the present invention is to provide a safety arrangement including a swivel mechanism to activate and change the tackle position.

Yet another object of the present invention is to provide a safety arrangement including a limit switch activated by the swivel mechanism.

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

In accordance with the present invention, there is provided a hoisting system with anti-rollover mechanism. The hoisting system includes an overhead hoist connected to a lifting frame by means of a hoist chain. A plurality of tackles are provided on the lifting frame for engagement with a heavy load carried on the conveyor system of the assembly line. The anti-rollover mechanism includes a plurality of limit switches. A swivel mechanism also is provided between the hoist chain and the lifting frame for ensuring the disengagement of all the tackles from under the heavy load before lifting the same from the conveyor system in an upward direction.

Typically, the plurality of tackles comprises at least four tackles with a respective hook integrally configured at the lower-end thereof for engagement / disengagement from under the heavy load to be hoisted from the conveyor system and/or for transferring the same to another location; one tackle each at the front and rear end of the heavy load to be lifted.

Typically, the anti-rollover hoisting system comprises:

• a swivel mechanism provided between the hoist chain and the lifting frame to actuate the limit switches;

• two relays provided in the overhead hoist control panel to control the hoist functions; and

• an indication lamp 11 provided in the overhead hoist control panel to indicate any abnormal condition of the heavy load being hoisted by the hoisting mechanism.

Typically, the swivel mechanism comprises a pivoting connection between the lifting frame to change the position of the tackle by tilting it to its side still remaining engaged to the heavy load.

Typically, the tackle tilted upwards activates the corresponding limit switch for arresting the upward movement to prevent any possible accident by falling down of the heavy load on the conveyor/hoist operator/s.
Typically, the activated limit switch issues a signal to one of the relays provided for stopping the hoisting movement of the load in the upward direction.

In accordance with the present invention, there is also provided a method for safe hoisting of heavy component or assembly being conveyed on an assembly line using the hoisting system with anti-rollover mechanism as claimed in anyone of the claim 1 to 6, wherein the method comprises the steps of:

• engaging the hooks of the tackles under the load, e.g. a heavy load, e.g. automotive vehicles;

• hoisting the lifting frame carrying the load;

• activating the limit switch by means of the swivel mechanism;

• displaying any abnormal condition of the heavy load resting on the hoisting mechanism by means of an indication lamp provided in the overhead hoist control panel;

• changing the position of the tackle to tilt is towards the side of the tackle remaining engaged under the heavy load, and in turn tilts the other side of the tackle upwards to activate the corresponding limit switch; and

• issuing a signal to one of the relays for stopping the hoisting movement.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

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

Figure 1 shows a schematic view of the conventional vehicle hoisting arrangement equipped in a vehicle assembly line conveyor.

Figure 2 shows another schematic arrangement of the vehicle hoisting mechanism equipped with a conventional hoist control system.

Figure 3 shows the occurrence of an accident with the conventional hoisting arrangement shown in Figure 1.
Figure 4 shows a schematic arrangement of the vehicle hoisting mechanism configured in accordance with the present invention.

Figure 5 shows a partial detailed view of the vehicle hoisting mechanism shown in Figure 3.

Figure 6 shows another detailed view of the swivel mechanism of the vehicle hoisting mechanism shown in Figure 3.

Figure 7 shows a view of the vehicle hoisting mechanism shown in Figure 3, to prevent vehicle from falling from the conveyor on non-removal of the tackle.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

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

Figure 1 shows a schematic arrangement of the vehicle hoisting mechanism equipped with a conventional hoist control system. The hoisting system includes a hoist 10, connected to the lifting frame 14 by means of a hoist chain 12. A plurality of tackles 16 are provided on the sides of the hoisting frame 14 for engaging with the heavy component or assembly to be lifted for transferring it between different work stations or storage area. Here, a vehicle body 18 is the assembly being lifted by means of the conventional hoisting system by engaging the LHS and RHS tackles 16 disposed under the vehicle body 18.

Figure 2 shows another schematic view of the conventional vehicle hoisting arrangement 10 equipped above a conveyor 30 (not visible here) used for assembly of vehicles 18. It includes a hoist control unit 20 operated by the hoist operator O1. Two more operators O2 and O3 are necessary to guide the hoist operator O1 for engagement and disengagement of the LHS and RHS tackles 16 under the vehicle 18 for lifting or releasing the vehicle body 18 on the mechanical line conveyor 30 by inserting the hooks 17 of the tackle 16 under the vehicle body 18. For lifting the vehicle body 18 upwards from the conveyor 30, all the lifting tackles 18 and their hooks 17 must be disengaged from the vehicle body 18. The control unit 20 includes two buttons, one for upward lifting of the load 18 on the lifting frame 14 and another one for lowering the load 18 on the conveyor 30.

Figure 3 shows the occurrence of an accident with the conventional hoisting arrangement of Figure 1. Although, the hoist operator O1 could see the tackle guiding operator O1 along the line of vision L1, but he was unable to see the position of the hook 17 of the tackle 16 along his line of vision L2 due to the presence of the control unit 20. Therefore, although the tackle guiding operator O3 on the right side could indicate to the hoist operator O1 the safe removal of the hook 17 of the tackle 16 present on RHS of the lifting frame 14, the hoist operator O1 could not see that the hook 17 on the LHS of the tackle 16 was not completely removed before lifting and he operated the control unit 20 to lift the lift frame 14 carrying the vehicle 18 by means of the hoist 10. This led to a major accident and the vehicle toppled from the lift frame 14 towards the guide operator O2 hitting him seriously, as schematically depicted in this figure.

Figure 4 shows a schematic arrangement of the vehicle hoisting mechanism 10 configured in accordance with the present invention. It includes a hoisting system 10 connected to the lifting frame consisting of LHS and RHS tackles 16 having a respective plurality of hooks 17 provided at their lower ends to be engaged or disengaged under the vehicle body 18 according to the requirement, as discussed above. In accordance with the present invention, there is a swiveling mechanism 100 provided between the hoist chain 12 and the tackles 16, which is shown in more details and described further below w.r.t. Figure 5.

Figure 5 shows an enlarged detailed view of the hoisting mechanism 100 provided with the lifting frame 14 as shown in Figure 4. This includes a respective limit switch 110 on either side of the lift frame 14 and a swivel mechanism 120 provided between the hoist chain 12 and the lifting frame 14. This mechanism is developed to avoid accidents occurring due to vehicle toppling by ensuring the disengagement of all hooks 17 of the tackles 16 from under the vehicle 18 before lifting the Hoist 100 in upward direction. The new integrated hoisting mechanism 100 consist of 4 main components, i.e. two limit switches 110 (one switch on either side of the lifting frame 14) each provided at the front and rear end of the lifting frame 14 to sense any change in position of the tackles 16; two 110VAC relay provided in the overhead hoist control panel 10 (Figure 4) to control the hoist functions; a swivel mechanism 120 to actuate the limit switches 110; and an indication lamp 11 provided in the overhead hoist control panel 10 to indicate any abnormal condition of the vehicle body 18 on the hoisting mechanism 100.

Figure 6 shows a detailed locational view of each limit switch 110 fitted on either side of the lifting frame 12 provided at the front and rear end of the lifting frame 14 of vehicle hoisting mechanism 100 shown in Figures 4 and 5.

Figure 7 shows a detailed locational view of the swivel mechanism 100 shown in Figure 6, in which the system prevents the vehicle 18 from falling from the conveyor 30 when any of the hook 17 of the lifting tackle 16 still remains engaged under the vehicle body 18 by the inadvertent error of guiding operator O2 or O3 or due to lack of visibility of the hooks to the hoist operator O1.

WORKING OF THE INVENTION:

According to the working of this new hoisting mechanism, whenever the hoist operator O1 operates the hoist 10 without ensuring the engagement or dis-engagement of all the hooks 17 of the tackles 16 from under vehicle body 18.

The swivel mechanism 120 activates and changes the position of the tackle 16 by tilting it to the side where tackle has remained inadvertently engaged to the vehicle body 18. The tackle 16 on the other side thus tilts upwards and activates the corresponding limit switch 110.

This arresting of the upward movement by the limit switch prevents the falling down of vehicle body 18 off/on the conveyor 30.

The activated limit switch 110 sends a signal to one of the 110VAC relays provided in the overhead hoist control panel 10, which in turn stops the hoisting movement in the upward direction.
TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The hoisting system with anti-rollover mechanism configured in accordance with the present invention has the following advantages:

• Toppling of the vehicle body on/off the conveyor is completely eliminated.

• Invisibility of the tackle hooks on the vehicle body to the hoist operator does not restrict the safe functioning thereof.

• Accurate positioning of the lifting frame is facilitated by limit switches in coordination with the swiveling mechanism.

• Operator and hoisting mechanism safety is substantially improved.

• Painted Body damages rework time will be reduced.

• No skilled operator is required, so the operation is deskilled.

• Any existing hoist can be converted into this safe body lifting mechanism.

• No programming of the system is required.
• It is a low-cost solution.

• Tampering of the system is not possible due to this mechanism.

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, and, 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 the embodiments described herein. Therefore, 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 hoisting system with anti-rollover mechanism, said hoisting system including an overhead hoist connected to a lifting frame by means of a hoist chain and a plurality of tackles provided on the lifting frame for engaging with a heavy load carried on the conveyor system of the assembly line; wherein the anti-rollover mechanism includes a plurality of limit switches, and a swivel mechanism is provided between the hoist chain and the lifting frame for ensuring the disengagement of all the tackles from under the heavy load before lifting the same from the conveyor system in an upward direction.

2. Hoisting system as claimed in claim 1, wherein the plurality of tackles comprises at least four tackles with a respective hook integrally configured at the lower-end thereof for engagement/disengagement from under the heavy load to be hoisted from the conveyor system and/or for transferring the same to another location; one tackle each at the front and rear end of said heavy load to be lifted.

3. Hoisting system as claimed in claim 1, wherein the anti-rollover hoisting system comprises:

• a swivel mechanism provided between the hoist chain and the lifting frame to actuate the limit switches;

• two relays provided in the overhead hoist control panel to control the hoist functions; and

• an indication lamp 11 provided in the overhead hoist control panel to indicate any abnormal condition of the heavy load being hoisted by the hoisting mechanism.

4. Hoisting system as claimed in claim 1, wherein the swivel mechanism comprises a pivoting connection between the lifting frame to change the position of the tackle by tilting it to its side still remaining engaged to the heavy load.

5. Hoisting system as claimed in claim 4, wherein said tackle tilted upwards activates the corresponding limit switch for arresting the upward movement to prevent any possible accident by falling down of said heavy load on the conveyor/hoist operator/s.

6. Hoisting system as claimed in claim 5, wherein said activated limit switch issues a signal to one of the relays provided for stopping the hoisting movement of said load in the upward direction.

7. A method for safe hoisting of heavy component or assembly being conveyed on an assembly line using the hoisting system with anti-rollover mechanism as claimed in anyone of the claim 1 to 6, wherein the method comprises the steps of:

• engaging the hooks of the tackles under the load, e.g. a heavy load, e.g. automotive vehicles;

• hoisting the lifting frame carrying said load;

• activating the limit switch by means of the swivel mechanism;

• displaying any abnormal condition of the heavy load resting on the hoisting mechanism by means of an indication lamp provided in the overhead hoist control panel;

• changing the position of the tackle to tilt is towards the side of the tackle remaining engaged under the heavy load, and in turn tilts the other side of the tackle upwards to activate the corresponding limit switch; and

• issuing a signal to one of the relays for stopping the hoisting movement.

Dated: this 01st day of March, 2016. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT