FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION (See section 10 and rule 13)
1. TITLE OF THE INVENTION:
"Crankshaft Microfinishing Machine"
2. APPLICANT:
(a) NAME: Grind Master Machines Pvt. Ltd.
(b)NATIONALITY: Indian Company registered under the
provisions of the Companies Act-1956
(c) ADDRESS: B10/B11/B14, MIDC, Railway Station,
Aurangabad 431005, Maharashtra, India
3. PREAMBLE TO THE DESCRIPTION:
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

Crankshaft Micro finishing Machine
Field of the invention
The present invention relates to a crankshaft microfinishing machine and more particularly, to an arm spacer for the crankshaft microfinishing machine.
Background of the invention
Microfinishing is an abrasion process in which a film backed abrasive is brought to stand against a workpiece which has been previously rough ground or turned. Microfinishing is a critical operation in manufacturing of crankshafts, a vital component of all automotive engines. Proper positioning of a microfinishing arm on surface of the workpiece to be polished is a very critical step of the microfinishing process. In the existing microfinishing machines, the arms are positioned manually depending on the size/design of the crankshaft. This manual adjustment of the machine is time consuming usually taking up to 2 hours and involves increased possibility of human errors.
Accordingly, there exists a need to provide a crankshaft microfinishing machine with an arm spacer that overcomes the drawbacks of the prior art.
Object of the invention
An object of the present invention is to reduce the manual adjustment effort and time involved for setup of a microfinishing machine in relation to a crankshaft to be
manufactured.

Summary of the invention
Accordingly the present invention provides a crankshaft micro finishing machine. The crankshaft microfinishing machine comprises a headstock unit, a tailstock unit. an arm-pack and a film management system having a film indexer. The arm-pack includes a plurality of microfinishing arm units and an arm spacer. Each arm unit of the plurality of microfinishing arm units includes a plurality of first cam sets, a plurality of second cam sets and a pair of arms. The plurality of first cam sets and the plurality of second cam sets are in co-axial alignment with each other. The arm spacer comprises an automatic actuation mechanism. The automatic actuation mechanism includes a hydraulic cylinder, a sprocket and a shaft. The hydraulic cylinder is capable of moving linearly and actuates the sprocket. The shaft is capable of rotating on actuation of the sprocket by the hydraulic cylinder. The shaft includes the plurality of first cam sets positioned thereon.
The motion of the hydraulic cylinder causes rotation of the plurality of first cam sets that gets translated into an axial movement of the plurality of second cam sets for engagement of the plurality of first set of cams with the plurality of second set of cams thereby decreasing the distance between the pair of arms of the each arm unit of the plurality of microfinishing arm units resulting in a closed configuration. The plurality of first cam sets is rotated by 120 degrees. Upon disengagement of the plurality of first cam sets from the plurality of second cam sets, the distance between the pair of arms of the each arm unit of the plurality of microfinishing arm units is increased resulting in forming an open configuration.
Brief description of the drawings
Figure 1 shows a layout of a crankshaft microfinishing machine, in accordance with

the present invention;
Figure 2 shows a perspective view of an arm unit of the crankshaft microfinishing machine of figure 1;
Figure 3 is a perspective view showing arrangement of cams on the arm unit of figure 2;
Figure 4 shows a side perspective view of a plurality of first set of cams and a plurality of second set of cams, in accordance with the present invention;
Figure 5A illustrates a close configuration when the plurality of first set of cams of figure 4 engages with the plurality of second set of cams of figure 4;
Figure SB illustrates an open configuration when the plurality of first set of cams of figure 4 disengages with the plurality of second set of cams of figure 4;
Figures 6A and 6B show respective side perspective views illustrating a plurality of co-axially aligned first cam sets and second cam sets, with all cams in open and closed configurations, in accordance with the present invention; and
Figures 7A and 7B show respective top cross sectional views illustrating an actuating mechanism of an arm spacer of the crankshaft microfinishing machine in open and closed configurations, in accordance with the present invention.
Detailed description of the invention
The foregoing objects of the present invention are accomplished and the problems •

and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.
The present invention provides a crankshaft micro finishing machine having an arm spacer. The arm spacer includes an automatic actuation mechanism that shifts and locks cams in different configurations so as to change the distance between a plurality of microfinishing arm units of the crankshaft microfinishing machine.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.
Referring to figures 1-7B. a crankshaft microfinishing machine (100) (hereinafter "the machine (100)") in accordance with the present invention is shown. The machine (100) comprises a headstock unit (20), a tailstock unit (40), an arm-pack (80) and a film management system (not numbered). The film management system includes a film indexer (90).
The arm-pack (80) includes a plurality of microfinishing arm units (not numbered) and an arm spacer (not numbered). Typically a four cylinder engine crankshaft includes nine arm units. Specifically, five arm units for main journals and four arm units for pin journals. The plurality of microfinishing arm units polishes features of the crankshaft using an abrasive film (not shown). The arm spacer adjusts the spacing between the plurality of microfinishing arm units. Each arm unit (50) of the plurality of microfinishing arm units includes a plurality of first cam sets (44), a plurality of second cam sets (46) and a pair of arms (48). The pair of arms (48) is positioned on the plurality of second cam sets (46).

The plurality of first cam sets (44) and the plurality of second cam sets (46) are in co-axial alignment with each other. Each cam of the plurality of first cam sets (44) is a cylindrical shaped structure and adapted to get engaged with the plurality of second cam sets (46). Each cam of the plurality of second cam sets (46) is a square shaped fixed cam. The plurality of first cam sets (44) and the plurality of second cam sets (46) include operative mating surfaces (42) that allow engagement of the plurality of first cam sets (44) with the plurality of second cam sets (46). In an embodiment, the plurality of first cam sets (44) is a rotational cam and the plurality of second cam sets (46) is a linear cam,
A first cam (not numbered) of the plurality of first cam sets (44) is in a naturally closed configuration. Further cams of the plurality of first cam sets (44) are in open configuration, initially as shown in figure 6B. As shown in figures 5A and 6B, the plurality of first cam sets (44) rotates and engages with the plurality of second cam sets (46) to transform into the closed configuration. Similarly, the disengagement of the plurality of co-axially aligned first cam sets (44) and second cam sets (46) results in opening of the structure as shown in figures 5B and 6A.
The arm spacer includes an automatic actuation mechanism (hereinafter "the actuation mechanism") (not shown). The arrangement of the plurality of co-axially aligned first cam sets (44) and second cam sets (46) on the machine (100) is changed by the actuation mechanism. The actuation mechanism comprises a hydraulic cylinder (52), a shaft (54) and a sprocket (not numbered). The hydraulic cylinder (52) moves linearly thereby rotating the shaft (54) by actuating the sprocket. The plurality of firm cam sets (44) are positioned on the shaft (54) and the plurality of second cam sets (46) are positioned on the pair of arms (48) of the each arm unit (50) of the plurality of microfinishing arm units. The rotation of the shaft (54) makes rotation of the plurality of first cam sets (44) thus resulting in a spacing

change.
Referring again to figures 1-7B, in an operation, the motion of the hydraulic cylinder (52) causes rotation of the plurality of first cam sets (44). In an embodiment, the plurality of first cam sets (44) is rotated by 120 degrees. The rotational movement of the plurality of first cam sets (44) translates into an axial movement of the plurality of second cam sets (46), in other words, the plurality of second cam sets (46) moves axially by the quantum rise in the plurality of first cam sets (44). As a result, the plurality of first cam sets (44) is engaged with the plurality of second cam sets (46) thereby decreasing the distance between the pair of arms (48) of the each arm unit (50) of the plurality of micro finishing arm units. Thus, the closed configuration is achieved as shown in figure 4B with a center distance equal to for example, about 37.75mm.
When the plurality of first cam sets (44) disengages from the plurality of second cam sets (46), the distance between the pair of arms (48) of the each arm unit (50) of the plurality of microfinishing arm units is increased. This results in forming an open configuration as shown in figure 4A with the center distance equal to for example, about 39.85mm. However, it is understood that the different centre distances may be achieved between the pair of arms (48) in other alternative embodiments of the machine (100).
Advantages of the present invention
1. The setup change time is reduced to about 20 minutes.
2. The solution is simple, low cost and elegant.

The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.

We Claim:
1. A crankshaft microfinishing machine comprising a headstock unit, a
tailstock unit, an arm-pack and a film management system having a film indexer,
the arm-pack having a plurality of microfinishing arm units and an arm spacer, each
arm unit of the plurality of microfinishing arm units includes a plurality of first cam
sets, a plurality of second cam sets and a pair of arms,
characterized in that the arm spacer comprising an automatic actuation mechanism having
a hydraulic cylinder being capable of moving linearly and
actuating a sprocket, and
a shaft being capable of rotating on actuation of the sprocket by the hydraulic cylinder, the shaft having the plurality of first cam sets positioned thereon,
wherein, motion of the hydraulic cylinder causes rotation of the plurality of first cam sets that gets translated into an axial movement of the plurality of second cam sets for engagement of the plurality of first set of cams with the plurality of second set of cams thereby decreasing the distance between the pair of arms of the each arm unit of the plurality of microfinishing arm units resulting in a closed configuration and upon disengagement of the plurality of first cam sets from the plurality of second cam sets, the distance between the pair of arms of the each arm unit of the plurality of microfinishing arm units is increased resulting in forming an open configuration.
2. The crankshaft microfinishing machine as claimed in claim 1 is
characterized in that the plurality of first cam sets is rotated by 120 degrees.

3. The crankshaft microfinishing machine as claimed in claim 1 is characterized in that plurality of first cam sets and the plurality of second cam sets are in co-axial alignment with each other.