Claims:1. A method of detecting the presence or absence of fasteners on either side of a gudgeon pin fitted to a piston, said method comprising:
removably passing a resilient plunger through said axial passage in said gudgeon pin such that the ends of said resilient plunger project out of said gudgeon pin at either end;
applying a pulling/pushing force on either of said projecting ends of said plunger;
sensing the displacement of said gudgeon pin under said applied force; and
determining the presence of said fasteners on either side of said gudgeon pin if the displacement is below a threshold limit and the absence of said fasteners by the displacement of said gudgeon pin if the displacement is beyond the threshold limit.

2. An apparatus for detecting the presence or absence of fasteners on either side of a gudgeon pin having an axial passage and fitted to a piston, said apparatus comprising:
a resilient plunger configured to removably pass through said axial passage in said gudgeon pin such that the ends of said plunger project out of said gudgeon pin at either ends, said plunger further configured to engage with ends of said gudgeon pin when a pulling/pushing force is applied on either of said projecting ends of said plunger by a force applicator;
at least one sensor configured to sense the displacement of said gudgeon pin under said applied force and further configured to transmit signals; and
a detector configured to receive said transmitted signals for determining the presence of said fasteners on either side of said gudgeon pin if the displacement of said gudgeon pin is below a threshold limit and the absence of said fasteners if the displacement of said gudgeon pin is beyond the threshold limit.
3. The apparatus as claimed in claim 2, wherein said detector comprises
a controller configured to receive said transmitted signals;
a comparator configured to compare magnitude of received transmitted signals with pre-defined magnitude stored in said comparator; and
an indicator configured to indicate the presence/absence of said fasteners through auditory, visual or a combination of auditory and visual means.

4. The apparatus as claimed in claim 2, wherein said resilient plunger extends from a shaft disposed within a housing, such that said shaft is received within a guide bush fixed within said housing, said shaft being displaceable along the length of said housing.

5. The apparatus as claimed in any of the preceding claims, wherein said at least one sensor includes a pair of proximity sensors that are mounted on said housing, configured to displace along with said housing under said applied force and are further configured to sense the displacement of said gudgeon pin by trying to detect a bush element, which is fixedly mounted on said shaft and located between said pair of proximity sensors, such that:
• if said bush element is detected by said pair of proximity sensors, then the displacement of said gudgeon pin is below a threshold limit, thereby implying the presence of said fasteners on either ends of said gudgeon pin; or
• if said bush element is not detected by said pair of proximity sensors, then the displacement of said gudgeon pin is beyond the threshold limit, thereby implying the absence of said fasteners on one end or both ends of said gudgeon pin.

6. The apparatus as claimed in claim 5, wherein in a first operative configuration, when said fasteners are provided at the operative ends of said gudgeon pin, said resilient plunger engages with said gudgeon pin to try to displace said gudgeon pin under said applied force, wherein the displacement of said gudgeon pin is restricted by said fasteners, thereby causing said bush element to be displaced proximal to either of said pair of proximity sensors that detects the presence of said bush element, and implying the presence of said fasteners.

7. The apparatus as claimed in claim 5, wherein in a second operative configuration, when said fasteners are not provided at either of the operative ends of said gudgeon pin, said plunger engages with said gudgeon pin to displace said gudgeon pin under said applied force, wherein the displacement of said gudgeon pin is not restricted due to absence of either one or both of said fasteners, thereby maintaining the location of said bush element between said pair of proximity sensors, and implying the absence of either one or both of said fasteners.

8. The apparatus as claimed in claim 5, which includes a resilient element configured to retract the movement of at least one of said bush element, said pair of proximity sensors, said housing and said shaft such that said bush element is relocated between said pair of proximity sensors.

9. The apparatus as claimed in any of the preceding claims, wherein said guide bush divides said housing into a first chamber and a second chamber, wherein said first chamber houses said bush element and said resilient element, and said second chamber houses a first and a second adjacent stopper configured to restrict the movement of said shaft within said housing.

10. The apparatus as claimed in claim 7, wherein said first adjacent stopper and second adjacent stopper are configured to abut said guide bush and said housing to restrict the movement of said shaft further towards said first chamber and said second chamber respectively. , Description:FIELD
The present disclosure relates to mechanical engineering, and particularly relates to fasteners used in a piston to prevent the movement of a gudgeon pin fitted in the piston.
BACKGROUND
A piston is a necessary and critical component of an internal combustion engine and is connected to a connecting rod that couples the piston with a crankshaft. The connecting rod and the piston are coupled via a pin, also known as “gudgeon pin”, which is received in a passage of the connecting rod. The surface of the piston contains a through hole that extends from one side to the other side. During the assembly of components of the internal combustion engine, the gudgeon pin enters one side of the through hole, passes through the passage of the connecting rod and extends to the other side of the through hole. The assembly or linkage between the connecting rod and the piston via the gudgeon pin is further secured by providing fasteners such as snap rings or circular clips on either side of the gudgeon pin. The fasteners are provided to restrict the movement of the gudgeon pin. However, under forces that are subjected upon the piston during operation, the gudgeon pin tends to displace and also has a tendency to dislodge from the assembled position in the absence of a fastener on one or both the sides of the gudgeon pin. The displaced/dislodged gudgeon pin comes in contact with the inner surface of a cylinder of the internal combustion engine while moving outwardly under the forces. This contact between the inner surface of the cylinder and the gudgeon pin gives rise to abrasion, heat, wear and tear resulting in ceasing of the internal combustion engine and sudden ceasing of the internal combustion engine leads to fatal accidents. Also, a lot of internal damage is caused to the engine and therefore, the repairing and maintenance cost is high. Besides, valuable reputation and trust that were built by the manufacturer over the years deteriorate quickly.
Therefore, there is a need for an apparatus and a method that limits the aforementioned drawbacks and detects the presence/absence of fasteners on either side of a gudgeon pin fitted to a piston.

OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide an apparatus that detects the presence/absence of fasteners on either side of a gudgeon pin in the assembly of an internal combustion engine.
Another object of the present disclosure is to provide an apparatus that detects and reduces manufacturing defects during the assembly of an internal combustion engine.
Still another object of the present disclosure is to provide an apparatus that reduces or eliminates the accidents caused due to absence of fasteners on either side of a gudgeon pin in the assembly of an internal combustion engine.
Yet another object of the present disclosure is to enhance safety and security by successfully detecting the presence/absence of fasteners on either side of a gudgeon pin in the assembly of an internal combustion engine.
Another object of the present disclosure is to provide a method and an apparatus that is easy to understand and use.
Still another object of the present disclosure is to provide an apparatus that reduces repairing and maintenance cost.
Other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying drawing, which are not intended to limit the scope of the present disclosure.

SUMMARY
An apparatus and a method for detecting the presence or absence of fasteners on either side of a gudgeon pin fitted to a piston. The apparatus comprises, a shaft disposed within a housing such that the shaft is received within a guide bush fixed within the housing, and is displaceable along the length of the housing, a resilient plunger that extends from the shaft and is configured to removably pass through an axial passage in the gudgeon pin such that the ends of the resilient plunger project out of the gudgeon pin at either ends, and are configured to engage with the ends of the gudgeon pin when a pulling/pushing force is applied on either of the projecting ends of the resilient plunger. The apparatus further comprises sensors that include a pair of proximity sensors which are fixedly mounted on the housing and are configured to displace along with the housing under the applied force to sense the displacement of the gudgeon pin by trying to detect the presence or absence of a bush element, which is fixedly mounted on the shaft and is located between the pair of proximity sensors in such a way that: (i) if the bush element is detected by the pair of proximity sensors, then the displacement of the gudgeon pin is below a threshold limit, thereby implying the presence of the fasteners on either ends of the gudgeon pin; and (ii) if the bush element is not detected by the pair of proximity sensors, then the displacement of the gudgeon pin is beyond the threshold limit, thereby implying the absence of the fasteners on one end or both ends of the gudgeon pin.
In a first operative configuration of the apparatus, when the fasteners are provided at the operative ends of the gudgeon pin, the resilient plunger engages with the gudgeon pin to try to displace the gudgeon pin under the applied force, wherein the displacement of the gudgeon pin is restricted by the fasteners, thereby causing the bush element to be displaced proximal to either of the pair of proximity sensors that detects the presence of the bush element, and implying the presence of the fasteners. In a second operative configuration of the apparatus, when the fasteners are not provided at either one or both of the operative ends of the gudgeon pin, the plunger engages with the gudgeon pin to displace the gudgeon pin under the applied force, wherein the displacement of the gudgeon pin is not restricted due to absence of either one or both of the fasteners, thereby maintaining the location of the bush element between the pair of proximity sensors, and implying the absence of either one or both of the fasteners. The apparatus includes a resilient element, which is configured to retract the movement of at least one of the bush element, the pair of proximity sensors, the housing and the shaft such that the bush element is relocated between the pair of proximity sensors.
The guide bush of the apparatus divides the housing into a first chamber and a second chamber, wherein the first chamber houses the bush element and the resilient element, and the second chamber houses a first and a second adjacent stopper configured to restrict the movement of the shaft within the housing. The first adjacent stopper is configured to abut the guide bush to restrict the movement of the shaft further towards the first chamber and the second adjacent stopper is configured to abut an end of the housing to restrict the movement of the shaft further towards the second chamber.
The fasteners on either side of the gudgeon pin fitted to the piston are selected from the group consisting of snap rings and circular clips. The guide bush and the bush element of the apparatus are fixed to the housing and the shaft respectively by a fixing element, which is selected from the group consisting of screws, nuts and bolts, and rivets.

BRIEF DESCRIPTION
An apparatus and a method of the present disclosure will now be described with the help of an accompanying drawing, in which:
Fig. 1 illustrates a sectional view of the apparatus that detects the presence/absence of fasteners on either side of a gudgeon pin fitted to a piston, in accordance with an embodiment of the present disclosure;
Fig. 2a illustrates a first part of a first operative configuration of the apparatus of Fig. 1;
Fig. 2b illustrates a second part of the first operative configuration of the apparatus of Fig. 1;
Fig. 2c illustrates a first part of a second operative configuration of the apparatus of Fig. 1;
Fig. 2c illustrates a second part of the second operative configuration of the apparatus of Fig. 1; and
Fig. 3 illustrates a block diagram representing the method for detecting the presence/absence of fasteners on either side of a gudgeon pin fitted to a piston, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
An apparatus and a method to detect the presence/absence of fasteners on either side of a gudgeon pin fitted to a piston, in accordance with a preferred embodiment of the present disclosure will now be described with reference to the embodiments, which do not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiment herein, the various features, and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced, and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
Fig. 1 illustrates a sectional view of an apparatus 100 that detects the presence/absence of fasteners (not shown in the figure 1) on either side of a gudgeon pin (not shown in the figure 1) fitted to a piston (not shown in the figure 1). The apparatus 100 comprises a housing 105, a guide bush 107, a first fixing element 108, a shaft 110, a plunger 115 with a pair of engaging stoppers 116 and 117, a resilient element 120, a bush element 125, a second fixing element 126, at least one sensor, a key way 130, a first adjusting stopper 135, a second adjusting stopper 140, and an end cap 145. An assembly of the components of the apparatus 100 and the interrelationships between the various components of the apparatus 100 are described hereinafter, in conjunction with the Figure 1.
The housing 105 is typically made of Teflon. The housing 105 of the apparatus 100 has a hollow cylindrical structure with openings at either ends, thereby creating a passage within the housing 105. The housing 105 is configured to receive various components of the apparatus 100 within the passage of the housing 105. The guide bush 107 is fitted within the housing 105 by means of the first fixing element 108 such that there is no relative motion between the fixed guide bush 107 and the housing 105. In one embodiment, the first fixing element can be selected from the group consisting of screws, nuts and bolts, rivets and other fasteners. In another embodiment, the guide bush 107 can be an integral part of the housing 105. The fixed guide bush 107 divides the housing 105 into two chambers, viz. a first chamber and a second chamber, hereinafter also referred as a control chamber C and a sensing chamber S. The guide bush 107 has a disc like structure with a hole at the center and is configured to receive the shaft 110 within the hole and is further configured to guide the movement of the shaft 110 along the length of the housing 105. The shaft 110 is disposed within the housing 105 from the opening configured on the side of the sensing chamber S such that the shaft 110 passes through the hole of the fixed guide bush 107 and is further extended into the control chamber C.
The plunger 115 is typically made of a resilient material and extends outwardly from the shaft 110. The plunger 115 is designed in such a way that the ends of the plunger 115 include the pair of engaging stoppers 116 and 117. The plunger 115 is configured to removably pass through an axial passage configured in the gudgeon pin (not shown in the Figure 1) such that the ends of the resilient plunger 115 project out of the gudgeon pin at either ends. The resilient plunger 115 is further configured to engage with ends of the gudgeon pin by means of the pair of engaging stoppers 116 and 117, hereinafter separately known as the first engaging stopper 116 and the second engaging stopper 117, when a pulling/pushing force is applied on either of the projecting ends of the resilient plunger 115 by a force applicator (not shown in the Figure). In one embodiment, the force applicator may apply the force automatically or can be applied manually. In another embodiment, the first and the second engaging stoppers can be a separate element fitted to the ends of the plunger, after the plunger passes through the axial passage of the gudgeon pin.
The bush element 125 of the apparatus 100 is fitted on a portion of the shaft 110 which is present inside the sensing chamber S. The bush element 125 is similar in construction to the guide bush 107 and therefore, constitutes a hole at the center. The bush element 125 allows the shaft 110 to pass through the hole provided at the center of the bush element 125 during the assembly of the apparatus 100, and later is fitted to the shaft 110 by the second fixing element 126 such that there is no relative motion between the bush element 125 and the shaft 110. In one embodiment, the second fixing element can be selected from the group consisting of screws, nuts and bolts, rivets and other fasteners. In another embodiment, the bush element 125 can be an integral part of the shaft 110. The diameter of the bush element 125 is kept smaller than the diameter of the guide bush 107 so as to allow the bush element 125 to slide along with the shaft 110, when the shaft 110 displaces within the hollow space of the housing 105 and also to prevent any unwanted contact between the housing 105 and the bush element 125.
The sensing chamber S also houses the resilient element 120 which is mounted on the shaft 110 inside the housing 105. The resilient element 120 is operatively connected to the bush element 125 and is configured to retract the movement of the bush element 125 to bring the bush element 125 back to the original position from where the movement of the shaft 110 started. A portion of the shaft 110 extending inside the control chamber C of the housing 105 is provided with the key way 130. The key way 130 is configured to facilitate linear displacement of the shaft 110 within the control chamber C, while the shaft 110 is guided by the fixed guide bush 107. The portion of the shaft 110, which is located in the control chamber C of the housing 105, includes the first adjusting stopper 135 and the second adjusting stopper 140 of the apparatus 100. The first adjusting stopper is also called the front stroke adjusting stopper 135 and the second adjusting stopper is also called the rear stroke adjusting stopper 140. The opening on the control chamber C is covered by means of the end cap 145. The front stroke adjusting stopper 135 is configured to abut the guide bush 107 to restrict the movement of the shaft 110 further towards the sensing chamber C under the applied force. The rear stroke adjusting stopper 140 is configured to abut the end cap 145 of the housing 105 to restrict the movement of the shaft 110 further towards the control chamber C under the applied force.
In an exemplary embodiment, the at least one sensor includes a pair of proximity sensors 128 and 129. The pair of proximity sensors 128 and 129 is mounted on the surface of the housing 105 and is located in the sensing chamber S portion of the housing 105. In one embodiment, positions of the pair of proximity sensors 128 and 129 can be changed and the pair of proximity sensors 128 and 129 can be re-fitted at different locations on the housing 105. The number of proximity sensors do not limit the scope of the disclosure and can include one or more than one proximity sensor. Each of the proximity sensors 128 and 129 are equidistantly placed from the bush element 125. The pair of proximity sensors 128 and 129 displaces along with the housing 105 under the applied force and is configured to detect the bush element 125, which is located between the pair of proximity sensors 128 and 129. The proximity sensors 128 and 129 are connected to a detector (not shown in the figures) and are configured to transmit signals when the presence/absence of the bush element 125 is detected. The detector includes a controller (not shown in the figures), a comparator (not shown in the figures) and an indicator (not shown in the figures). The controller is configured to receive the transmitted signals and provide the received signal to the comparator. The comparator is configured to compare the magnitude of received transmitted signals with pre-defined magnitude stored in the comparator for determining the presence of the fasteners on either side of the gudgeon pin if the displacement of the gudgeon pin is below a threshold limit and the absence of the fasteners if the displacement of the gudgeon pin is beyond the threshold limit. The indicator is configured to indicate the presence/absence of the fasteners through auditory, visual or a combination of auditory and visual means, in accordance with the comparison made by the comparator.
For example, in one scenario, if the bush element 125 is detected by any one of the pair of proximity sensors 128 and 129, then the displacement of the gudgeon pin is below a threshold limit in the direction of the applied force, thereby implying the presence of the fasteners on respective ends of the gudgeon pin. In another scenario, if the bush element 125 is not detected by the pair of proximity sensors 128 and 129, then the displacement of the gudgeon pin is beyond the threshold limit in the direction of the applied force, thereby implying the absence of the fasteners at the respective ends of the gudgeon pin.
Fig. 2A, 2B, 2C and 2D illustrates an assembly 150 of an apparatus 200 with component of an internal combustion engine (not shown in the figures) such as a piston 217, a gudgeon pin 216, a first fastener 218 and a second fastener 219, in different operational configurations. The assembly and functioning of the components of the apparatus 200 is similar to that of the apparatus 100. The apparatus 200 comprises a housing 205, a guide bush 207, a shaft 210, a plunger 215 with a pair of engaging stoppers 213 and 214, a resilient element 220, a bush element 225, a pair of proximity sensors 228 and 229. The apparatus 200 is disposed horizontally by means of a pliable holder (not shown in the figures) hanging from an upper portion of an assembly line (not shown in the figures). The pair of engaging stoppers 213 and 214 hereinafter will also be referred as the first end 213 and the second end 214 of the plunger 215. During the assembly 150 of the components of the internal combustion engine, a connecting rod (not shown in the figure) and the piston 217 are coupled via the gudgeon pin 216, which is received in a passage of the connecting rod. The surface of the piston 217 contains a through hole that extends from one side to the other side. The resilient plunger 215 of the apparatus 200 is configured to removably pass through an axial passage configured in the gudgeon pin 216 such that ends 213, 214 of the resilient plunger 215 project out of the gudgeon pin 216 at either ends. The gudgeon pin 216 along with the resilient plunger 215 are made to enter from one side of the through hole of the piston 217, passes through the passage of the connecting rod and extends to the other side of the through hole of the piston 217. The assembly 150 or linkage between the connecting rod and the piston 217 via the gudgeon pin 216 is further secured by providing the first and the second fasteners 218, 219 on either side of the gudgeon pin 216. In one embodiment, the first and the second fasteners can be selected from the group of snap rings, circular clips and the like. The first and the second fasteners 218, 219 are provided to restrict the movement of the gudgeon pin 216 under a pulling/pushing force applied on the assembly 150 of the apparatus 200 and the gudgeon pin 216. The gudgeon pin 216 is held in position if the first and the second fasteners 218, 219 exist on either side of the gudgeon pin 216. The first and the second fasteners 218,219 are configured to expand and securely lock themselves within a cavity (not shown in the figures) provided inside a piston head (not shown in the figures) of the piston 217. The apparatus 200 is provided with a grip like feature near an end cap of the housing 205 of the apparatus 200 so as to facilitate easy holding of the apparatus 200 and to increase the efficiency of the functions associated with various components involved in the assembly 150.
Fig. 2A illustrates a first part of a first operative configuration of the apparatus 200 of Fig. 1. A pulling force is applied on the apparatus 200 in an operative forward direction, represented by ‘X’ in the figure 2A. Under the influence of the pulling force, the first end 213 of the plunger 215 tries to displace the gudgeon pin 216 towards the direction of the force, thereby acting against the first fastener 218 of the assembly 150. As the force on the apparatus 200, applied through the housing 205, is gradually raised and maintained for a predetermined time period ‘t’, the presence of the first fastener 218 is determined by sensing the displacement of the gudgeon pin 216 to be below a threshold limit. Since, the housing 205 and the shaft 210 are not fixed and are allowed to have relative motion, therefore, the bush element 225 relatively displaces towards the first proximity sensor 228 in a “Y” direction as shown in figure 2A. The displacement of the gudgeon pin 216 to be below the threshold limit is determined when the first proximity sensor 228 senses the presence of the bush element 225 and still the displacement of the gudgeon pin 216 has not exceeded the threshold limit. The first proximity sensor 228 transmits a signal to a controller (not shown in the figures) to indicate the presence of the first fastener 218 at the respective end of the gudgeon pin 216, by activating a corresponding indication of auditory, visual or other sensory character. In one embodiment, the presence of the first fastener 218 at the corresponding operative end of the gudgeon pin 216 can be determined by analyzing the relative displacement between the bush element 225 and the first proximity sensor 228. Upon releasing the applied force on the housing 205 of the apparatus 200, the resilient element 220 retracts the movement of at least one of the following elements: the bush element 225, the first proximity sensor 228, the housing 205, and the shaft 210, such that the bush element 225 is relocated between the pair of proximity sensors 228, 229.
Fig. 2B illustrates a second part of the first operative configuration of the apparatus 200 of Fig. 1. A pushing force is applied on the apparatus 200 in an operative forward direction, represented by ‘Y’ in the figure 2B. Under the influence of the corresponding pushing force, the second end 214 of the plunger 215 tries to displace the gudgeon pin 216 towards the direction of the force, thereby acting against the second fastener 219 of the assembly 150. As the pushing force on the apparatus 200, applied through the housing 205, is gradually raised and maintained for a predetermined time period ‘t’, the presence of the second fastener 219 is determined by sensing the movement of the gudgeon pin 216 to be below a threshold limit. Since, the housing 205 and the shaft 210 are not fixed and are allowed to have relative motion, therefore, the bush element 225 relatively displaces towards the second proximity sensor 229 in a “X” direction as shown in figure 2B. The displacement of the gudgeon pin 216 to be below the threshold limit is determined when the second proximity sensor 229 senses the presence of the bush element 225 and still the displacement of the gudgeon pin 216 has not exceeded the threshold limit. The second proximity sensor 229 transmits a signal to the controller (not shown in the figures) to indicate the presence of the second fastener 219 at the respective end of the gudgeon pin 216, by activating a corresponding indication of auditory, visual or other sensory character. In one embodiment, the presence of the second fastener 219 at the corresponding operative end of the gudgeon pin 216 can be determined by analyzing the relative displacement between the bush element 225 and the first proximity sensor 228. Upon releasing the applied force on the housing 205 of the apparatus 200, the resilient element 220 retracts the movement of at least one of the following elements: the bush element 225, the second proximity sensor 229, the housing 205, and the shaft 210, such that the bush element 225 is relocated between the pair of proximity sensors 228, 229.
Fig. 2C illustrates a first part of a second operative configuration of the apparatus 200 of Fig. 1. A pulling force is applied on the apparatus 200 in an operative forward direction, represented by ‘X’ in the figure 2C. Under the influence of the pulling force, the first end 213 of the plunger 215 tries to displace the gudgeon pin 216 towards the direction of the force. Since, in this scenario, the first fastener 218 is absent, therefore, the gudgeon pin 216 displaces towards the direction of the force. As the force on the apparatus 200, applied through the housing 205, is gradually raised and maintained for a predetermined time period “t”, the gudgeon pin 216 gets further displaced beyond the threshold limit. Since, the housing 205 and the shaft 210 are not fixed and are allowed to have relative motion, therefore, there should be a relative motion between the bush element 225 and the first proximity sensor 228 under the influence of the applied force. Since, there is no relative motion between the bush element 225 and the first proximity sensor 228, therefore the first proximity sensor 228 does not sense the presence of the bush element 225 during the pre-determined time period “t”, and therefore, transmits a signal to a controller (not shown in the figures) to indicate the absence of the first fastener 218 at the respective end of the gudgeon pin 216, by activating a corresponding indication of auditory, visual or other sensory character. In one embodiment, the absence of the first fastener 218 at the corresponding operative end of the gudgeon pin 216 can be determined by directly analyzing the relative displacement between the bush element 225 and the first proximity sensor 228.
Fig. 2D illustrates a second part of the second operative configuration of the apparatus 200 of Fig. 1. A pushing force is applied on the apparatus 200 in an operative rearward direction, represented by ‘Y’ in the figure 2D. Under the influence of the pushing force, the second end 214 of the plunger 215 tries to displace the gudgeon pin 216 towards the direction of the force. Since, in this scenario, the second fastener 219 is absent, therefore, the gudgeon pin 216 displaces towards the direction of the force. As the force on the apparatus 200, applied through the housing 205, is gradually raised and maintained for a predetermined time period “t”, the gudgeon pin 216 gets further displaced beyond the threshold limit. Since, the housing 205 and the shaft 210 are not fixed and are allowed to have relative motion, therefore, there should be a relative motion between the bush element 225 and the second proximity sensor 229 under the influence of the applied force. Since, there is no relative motion between the bush element 225 and the second proximity sensor 229, therefore the second proximity sensor 229 is not able to sense the presence of the bush element 225 during the pre-determined time period “t”, and therefore, transmits a signal to a controller (not shown in the figures) indicating the absence of the second fastener 219 at the respective end of the gudgeon pin 216, by activating a corresponding indication of auditory, visual or other sensory character. In one embodiment, the absence of the second fastener 219 at the corresponding operative end of the gudgeon pin 216 can be determined by directly analyzing the relative displacement between the bush element 225 and the second proximity sensor 229.
Fig. 3 illustrates a block diagram representing the method 300 for detecting the presence/absence of fasteners on either side of a gudgeon pin fitted to a piston. Block 302 represents removably passing a resilient plunger through an axial passage in the gudgeon pin such that the ends of the resilient plunger project out of the gudgeon pin at either end of the gudgeon pin.
Block 304 represents applying a pulling/pushing force on either of the projecting ends of the resilient plunger.
Block 306 represents sensing the displacement of the gudgeon pin under the applied force.
Block 308 represents the function of determining the presence of the fasteners on either side of the gudgeon pin if the displacement is below a threshold limit and the absence of the fasteners by the displacement of the gudgeon pin if the displacement is beyond the threshold limit.

The apparatus 100 and/or the method 300 accurately detects the presence/absence of fasteners on either side of a gudgeon pin fitted to a piston and therefore have various technological and economic advantages such as –
? It detects the presence/absence of the fasteners and reduces errors during the assembly of the fasteners on either side of the gudgeon pin;
? It reduces or eliminates the accidents caused due to the absence of the fasteners on either side of the gudgeon pin;
? It enhances safety and security by successfully detecting the presence/absence of the fasteners on either side of the gudgeon pin;
? It is easy to understand the method 300 and functioning of the apparatus 100; and
? It reduces repairing and maintenance cost.
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 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, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The apparatus and the method, in accordance with the present disclosure described herein above has several technical and/or economic advantages including but not limited to the realization of an apparatus and a method that:
? detects the presence/absence of fasteners on either side of a gudgeon pin in the assembly of an internal combustion engine;
? detects and reduces errors during the assembly of fasteners in an internal combustion engine on either side of a gudgeon pin;
? reduces or eliminates the accidents caused due to absence of fasteners on either side of a gudgeon pin in the assembly of an internal combustion engine;
? enhances safety and security by successfully detecting the presence/absence of fasteners on either side of a gudgeon pin in the assembly of an internal combustion engine;
? is easy to understand and use; and
? reduces repairing and maintenance cost.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or mixtures or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the disclosure, as it existed anywhere before the priority date of this application. The numerical value mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the invention, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.