Claims:
1. A system for loading and unloading of a workpiece on a die of press machine, the die includes a first die shoe and a second die shoe for processing the workpiece, the system comprising:
a loading mechanism for loading of a workpiece on the second die shoe (120), the loading mechanism includes a first block (130) attached to the first die shoe (110) and a second block (140) attached to the second die shoe (120), the second block (140) includes a first spring (200) attached at a first end thereof, and a piston rod (220) that pushes the workpiece (180) on the second die shoe (120) at other end thereof; and
an unloading mechanism including a supply pipe (310) positioned through the second die shoe (120), the supply pipe (310) connected to a cylinder supplying a compressed air for moving a processed workpiece (390) from a die cavity (160) configured on the second die shoe (120), the die cavity (160) includes a second spring (161) placed therein, the cylinder is operated by engagement and disengagement of an upper lever (320) and a lower lever (340), the unloading mechanism works in synchronization with loading mechanism by engagement and disengagement of the first block (130) with the second block (140) and the upper lever (320) with the lower lever (340).
2. The system (100) as claimed in claim 1, wherein the first spring (200) is attached to a rigid frame (260) at second end of the first spring (200).

3. The system as claimed in claim 1, wherein the upper lever (320) is attached to the first die shoe (110) and the lower lever (340) is attached to the second die shoe (120).

4. A method for loading and unloading workpiece on a press machine, the method comprising the steps of:
loading a workpiece from a container (150) on a second die shoe (120) by disengaging a first block (130) attached to the first die shoe (110) with a second block (140) attached to the second die shoe (120);
processing the workpiece (180) loaded on the second die shoe (120) by moving the first die shoe (110) towards the second die shoe (120); and
unloading the processed workpiece (390) from the second die shoe (120) by disengagement of an upper lever (320) attached to the first die shoe (110) with a lower lever (340) attached to the second die shoe (120).

5. The method as claimed in claim 4, wherein the disengagement of the upper lever (320) and the lower lever (340) actuates a cylinder supplying compressed air through a supply pipe (310) positioned through the second die shoe (120) thereby moving the processed workpiece (390) from a die cavity (160) of the second die shoe (120).

6. The method as claimed in claim 5, wherein the die cavity (160) includes a second spring (161) that pushes the processed workpiece (390) such that lowermost surface of the processed workpiece (390) matches with a surface of the second die shoe (120).

7. The method as claimed in claim 4, wherein the second block (140) includes a piston rod (220) at one end thereof and a first spring (200) at other end thereof, disengagement of the second block (140) with the first block (130) releases the first spring (200) thereby pushing the workpiece (180) from the container (150) by the piston rod (220) connected to the second die shoe (120).
, Description:FORM 2
The Patents Act 1970
(39 of 1970)
&
The Patents Rules, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

SYSTEM AND METHOD FOR LOADING AND UNLOADING OF A WORKPIECE IN A PRESS MACHINE;

MAHINDRA & MAHINDRA LIMITED,
A COMPANY REGISTERED UNDER THE INDIAN COMPANIES ACT, 1913, HAVING ADDRESS AT MAHINDRA RESEARCH VALLEY (MRV), MAHINDRA WORLD CITY, PLOT NO: 41/1, ANJUR P.O., CHENGALPATTU – 603004, KANCHEEPURAM DIST., TAMIL NADU, INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

TECHNICAL FIELD OF THE INVENTION
The present invention relates a press machine and more particularly, to a system and a method for loading and unloading the workpiece on the press machine.

BACKGROUND OF THE INVENTION
A press machine is used in the manufacturing industry to deform a workpiece under high pressure. The press machine includes a die having two die shoes. The workpiece is loaded on one die shoe and operated under high pressure exerted by another die shoe. Conventionally, the loading of the workpiece on the die shoe and unloading of the processed workpiece from the press machine is done manually. Manual loading and unloading reduces the speed of overall operation cycle and may cause risk to the skilled/ unskilled operator.
To avoid the manual loading, some dies have slope at the start so that the workpiece slides down and fits into a die cavity once loaded manually at the beginning. Further, some press machines have roller springs which would force the workpiece into the cavity once placed manually at the starting position. However, such systems may cause fatigue due to load and unload the workpiece in die.
Presently, robots are used for loading and unloading operation however, they have to be programmed according to the position of the die on the machine and also according to the stacking position of workpiece near to the machine. In such case if the machine gets into breakdown the whole setup gets wasted.
In view of this, it is understood that automatic loading and unloading techniques in current state of art have two drawbacks: first, the manual loading of the part still stays active. Second, the unloading mechanism can be implemented only for the machine and not for the die.
Accordingly, there is need of an automated loading and unloading system for press machine that will overcome the drawbacks of the current state of art.

SUMMARY OF THE INVENTION
In one aspect, the present invention provides a system for loading and unloading of a workpiece on a die of a press machine. The die includes a first die shoe and a second die shoe for processing the workpiece. The system includes a loading mechanism for automatic loading of a workpiece on the second die shoe. The loading mechanism includes a first block attached to the first die shoe and a second block attached to the second die shoe. The second block includes a first spring attached at a first end thereof, and a piston rod that pushes a workpiece on the second die shoe at other end thereof. An unloading mechanism includes a supply pipe positioned through the second die shoe. The supply pipe is connected to a cylinder supplying a compressed air for moving a processed workpiece from a die cavity configured on the second die shoe. The cylinder is operated by engagement and disengagement of an upper lever and a lower lever. The loading mechanism and the unloading mechanism work in synchronization with each other by engagement and disengagement of the first block with the second block and the upper lever with the lower lever.
The die cavity includes a second spring for pushing the processed workpiece in upward direction. The first spring is attached to a rigid frame at second end of the first spring. The upper lever is attached to the first die shoe and the lower lever is attached to the second die shoe.
In another aspect, the present invention provides a method for loading and unloading workpiece on the press machine. In the first step, a workpiece from a container is loaded on a second die shoe by disengaging a first block attached to the first die shoe with a second block attached to the second die shoe. In the next step, the workpiece loaded on the second die shoe is processed by moving the first die shoe towards the second die shoe. In the next step, the processed workpiece is unloaded from the second die shoe by disengagement of an upper lever attached to the first die shoe with a lower lever attached to the second die shoe.

The disengagement of the upper lever and the lower lever actuates a cylinder supplying compressed air through a supply pipe positioned through the second die shoe thereby moving the processed workpiece from a die cavity of the second die shoe. The die cavity includes a second spring that pushes the processed workpiece such that lowermost surface of the processed workpiece matched with a surface of the second die shoe. The second block includes a piston rod at one end thereof and a first spring at other end thereof. Disengagement of the second block with the first block releases the first spring thereby pushing the workpiece from the container by the piston rod connected to the second die shoe.

BRIEF DESCRIPTION OF DRAWINGS
Embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
FIG. 1 shows a press machine, in accordance with an embodiment of the present invention;
FIG. 2 shows the press machine depicting loading of a workpiece in a die cavity; and
FIGS. 3 illustrates the press machine depicting the unloading of a workpiece form a die to storage bin.

DETAILED DESCRIPTION OF THE INVENTION
Although specific terms are used in the following description for sake of clarity, these terms are intended to refer only to particular structure of the invention selected for illustration in the drawings and are not intended to define or limit the scope of the invention.

References in the specification to “an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

In general aspect, the present invention discloses a system for loading and unloading of a workpiece in a die of press machine, which provides safety to the operator and portability feature to the die along with the complete. Further, the present invention discloses a method of loading and unloading of a workpiece in die of press machine.

Referring now to the drawings, and more particularly to FIGS. 1 through 3, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.

Referring to FIGS. 1-3, a system (100) for loading and unloading of a workpiece (180) on a die of a press machine is shown. The system (100) includes a loading mechanism and an unloading mechanism. The loading mechanism includes a first die shoe (110) and a second die shoe (120), a container (150) for storing said at least one workpiece (180).

The first die shoe (110) includes a first block (130) fixed thereto at a predefined position. In an embodiment, the second die shoe (120) includes a second block (140) positioned thereon by means of a first spring (200) and a piston rod (220). The first spring (200) is attached to the second block (140) on one side thereof, other side of the first spring (200) is attached to a rigid frame (260). The second block (140) has the piston rod (220) attached on other side thereof, other end of the piston rod (220) is attached to the container (150). The piston rod (220) is adapted to push one workpiece from the container (150) on the second die shoe (120). A shape of the first block (130) is complementary to the second block (140).

In accordance with an embodiment, the unloading mechanism includes a pneumatic pipe (310) placed through the second die shoe (120), an upper lever (320) attached on the first die shoe (110), and a lower lever (340) attached to the second die shoe (120). A die cavity (160) is configured on the second die shoe (120). The die cavity (160) includes a second spring (161) placed therein. The unloading mechanism further includes a storage bin (360) placed on a lower side of the second die shoe (120) for collecting the unloaded processed workpieces.

In operation, in default configuration, the first die shoe (110) and the second die shoe (120) are away from in each other. As the operation cycle initiates, the first die shoe (110) moves towards the second die shoe (120). The first block (130) attached to the first die shoe (110) gets engaged with the second block (140) thereby pushing the second block (140) towards the rigid frame (260) by compressing the first spring (200). As the second block (140) moves towards the rigid frame (260), the piston rod (220) attached thereto moves away from the container (150). It is to be noted here that in default condition, the piston rod (220) occupies the place of the lowermost workpiece in the stack of the workpieces placed in the container (150). As the piston rod (220) moves away from the stack of workpieces; the workpiece occupies the lowermost place in the container (150).

In next step, as the first die shoe (110) moves away from the second die shoe (120), the first block (130) gets disengaged with the second block (140). The first spring (200) pushes the second block (140) towards the container (150). The piston rod (220) pushes the lowermost workpiece (180) into the die cavity (160) from the stack of workpieces stored in the container (150). The processing of the workpiece takes place during simultaneous stroke of the first die shoe (110). At this stage, the second springs (161) placed in the die cavity (160) get pressed by the force exerted by the first die shoe (110) on the workpice (180) under process. In accordance with an embodiment, weight the processed workpiece (390) ranges from about 100 grams to about 350 grams. The processed workpiece (390) may have size of approximately 65mm length and 40 mm width with thickness of 1-1.5 mm.

In accordance with the unloading of a workpiece form a die to storage bin (360), when the first die shoe (110) moves away for the second die shoe (120), the force exerted by the first die shoe (110) on the workpiece under process is released. The second spring (161) pushes the processed workpiece (390) in upward direction. In this configuration, the lowermost portion of the processed workpiece (390) matches with the surface level of the second die shoe (120). The upper lever (320) attached to the first die shoe (110) disengages from the lower lever (340). The disengagement of the upper lever (320) and the lower lever (340) actuates a motor operated cylinder (not shown) for ejecting the high-pressure air/compressed air through the supply pipe (310). In an embodiment, the distance between the nozzle of the supply pipe (310) and the position of the processed workpiece (390) ranges between 5 mm to 15 mm. The high pressure air displaces/unloads the processed workpiece from the second die shoe (120) to the storage bin (360). In an embodiment, the compressed air is supplied by the pressure between 2-5 bar depending upon the weight and size of the processed workpiece (390).

In the next step, when the first die shoe (110) moves towards the second die shoe (120), the upper lever (320) gets engaged with the lower lever (340) thereby de-activating the motor configured to eject high pressure air from the pneumatic pipe (310). Thus, as soon as the ram completes one cycle, a new workpiece is already placed into the die cavity which is ready to be processed. This cycle continuously gets carried out until the stack of workpiece is finished and a new stack workpiece is placed.

List of reference numerals
100
110
120
130
140
150
160
161
180
200
220
260
310
320
340
360
390 Die system
First die shoe
Second die shoe
First block
Second block
container stack
Die cavity
Second Spring
work piece
First Spring
Piston rod
Frame
Supply Pipe
Upper lever
Lower lever
Storage bin
Processed workpiece