Piston wire lock and tool for inserting and removing the same

An anti-rotation wire lock for use in a piston to reduce rotation of the anti-rotation wire lock while seated inside a wrist pin lock groove of the piston. The anti-rotation wire lock includes a wire lock body which curls from a first end of the wire lock body and a second end which extends in a direction out of a plane defined by the curled wire lock body. In addition, wire lock tools are disclosed for inserting and removing the anti-rotation wire lock.

FIELD

The present invention relates to a piston assembly in an internal combustion engine, compressor, or the like. More specifically, the present invention relates to a piston including an anti-rotation wire lock and a tool for inserting and removing the same.

BACKGROUND

Each year, consumers purchase motor vehicles, such as automobiles, motorcycles, boats and planes, from many different manufacturers. With each motor vehicle costing thousands of dollars, there is intense competition between manufacturers to produce motor vehicles which can run faster and are more reliable. However, when producing motor vehicles that run faster, inevitably, the engines must run at a faster rate. The increased operation of the engine translates into an increased operation of the piston and the components of the piston. More specifically, when moving the piston, a wrist pin is generally rotated and the more the piston moves, the greater the rate of rotation of the wrist pin. This is problematic in that the rotation of the wrist pins can also cause a conventional wire lock to rotate at an increased rate. The friction caused by the rotation of the conventional wire lock can deform the wrist pin lock groove where the conventional wire lock is secured. Deformation of the wrist pin lock groove can be catastrophic and can cause the wrist pin to malfunction and/or cause other problems. In some instances, the wrist pin may actually force its way out of the wrist pin lock groove. At high operations and rotations, a malfunction of the wrist pin can permanently or semi-permanently damage the piston.

Thus, conventional motor vehicles can have problems with reliability due to the rotation of the conventional wire lock and deformations caused by the rotation of the conventional wire lock. However, the conventional wire lock presents additional problems, too. When the conventional wire lock needs to be replaced, it is often difficult to retrieve them due to their propensity to rotate. Thus, users may use sharp objects in an attempt to pry the conventional wire lock away from the wrist pin lock groove. This can cause additional and sometimes severe damage to the piston.

While the damage caused by the conventional wire lock may appear to be minor or insignificant, any breach to the wrist pin lock groove can have catastrophic results to the piston and ultimately the engine. In such competitive motor vehicle markets, consumers will be unhappy with a motor vehicle which requires frequent engine repair or replacement.

Such problems can be further illustrated inFIG. 1, which shows a piston200including a piston body102defining an aperture104. The aperture104is configured to receive a wrist pin (not shown). The piston body102also defines a wrist pin lock groove106for receiving a conventional wire lock108. In addition, the piston body102also defines a pick lock notch110. The pick lock notch110can be used to remove the conventional wire lock108from the wrist pin lock groove106.

Although the conventional wire lock108fits into the wrist pin lock groove106through tension, rotation of the wrist pin in a direction indicated by arrow122, for example, may cause the conventional wire lock108to rotate in the wrist pin lock groove106. As shown inFIG. 1, there is no mechanical device to physically lock the conventional wire lock108into a substantially singular location. Thus, when a piston is reciprocating at high velocities and high rotations per minute, the wrist pin is also spinning at high rates. Since the wrist pin is located in the aperture104, it is in contact with the conventional wire lock108. This contact generally forces the conventional wire lock108to rotate within the wrist pin lock groove106. The rotation of the conventional wire lock108within the wrist pin lock groove106causes deformation of the wrist pin lock groove106and possibly even engine failure due to the wrist pin forcing its way beyond the conventional wire lock108. In addition, the conventional wire lock108can be rotated to a position such that the removal and replacement of the conventional wire lock108can be hazardous to the piston.

SUMMARY

The present application generally concerns an anti-rotation wire lock, a piston assembly including an anti-rotation wire lock, and tools for inserting and removing a wire lock. The anti-rotation wire lock of the present disclosure addresses the deformation concerns discussed above by ordinarily reducing the amount of wire lock rotation during operation of the piston. This allows the piston and the engine to function at a higher level without damaging the piston or the engine. As previously noted, such damage to the piston or the engine can cost the consumer a substantial amount of money to repair or replace the engine.

According to one embodiment, an anti-rotation wire lock includes a wire lock body which curls from a first end of the wire lock body and a second end which extends in a direction out of a plane formed by the curled wire lock body. With this configuration, it is ordinarily possible for the second end to fit into the pick lock notch and thereby reduce rotation of the anti-rotation wire lock in the wrist pin lock groove.

In addition, the foregoing configuration ordinarily facilitates insertion and removal of the anti-rotation wire lock with less rotation than for a conventional wire lock, thereby making insertion and removal of the anti-rotation wire lock easier. Thus, users who want to replace the anti-rotation wire lock can remove the anti-rotation wire lock in an easy manner with minimal contact to the wrist pin lock groove from sharp objects. This minimal contact further reduces the chances that the wrist pin lock groove will be damaged.

To further simplify the removal process and to further protect the wrist pin lock groove, the present disclosure also includes embodiments of a wire lock tool for insertion and removal of a wire lock. According to one embodiment, a wire lock tool includes a shaft having an insertion end defining a through hole constructed to mate with a first end of a wire lock and a removal end on a side opposite the insertion end and defining a blind hole constructed to mate with a bent end of the wire lock.

According to another embodiment of a wire lock tool, the wire lock tool includes a shaft and a handle connected to the shaft on one end of the shaft. The shaft includes a blind hole on an end portion of the shaft opposite the handle and the blind hole is constructed to mate with a bent end of a wire lock.

The use of the foregoing wire lock tools for inserting and removing a wire lock ordinarily reduces the need to use sharp tools which may damage the wrist pin lock groove. Furthermore, the foregoing wire lock tools can also facilitate the easy insertion and removal of the anti-rotation wire lock, which can reduce time spent replacing a wire lock. This can also further increase cost savings associated with the use of the anti-rotation wire lock.

Such advantages provided by the anti-rotation wire lock and tools of the present disclosure can improve the reliability of motor vehicles produced by manufacturers, and in some instances, allow manufacturers to increase the performance of the motor vehicle. Furthermore, the use of the anti-rotation wire lock and tools of the present disclosure can increase confidence in consumers purchasing motor vehicles, resulting in higher sales.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are set forth to provide a full understanding of the present invention. It will be apparent, however, to one ordinarily skilled in the art that the present invention may be practiced without some of these specific details. In other instances, well-known structures and techniques have not been shown in detail to avoid unnecessarily obscuring the present invention.

FIG. 2illustrates a close-up view of a piston including an anti-rotation wire lock according to an embodiment of the present invention. The piston200includes a piston body102defining an aperture104. The aperture104is configured to receive a wrist pin (such as wrist pin112inFIG. 4). The piston body102also defines a wrist pin lock groove106for receiving an anti-rotation wire lock208. In addition, the piston body102also defines a pick lock notch110. Both the wrist pin lock groove106and/or the pick lock notch110are part of the aperture104. The pick lock notch110can be used to remove the anti-rotation wire lock208from the wrist pin lock groove106.

As shown inFIG. 2, the wire lock body216of the anti-rotation wire lock208is configured to be placed into the wrist pin lock groove106. Such placement may be accomplished through tension of the wire lock body216, which is generally in a “C” shape. Second end214is configured to be placed into the pick lock notch110, thereby reducing rotation of the wire lock body216even when the wrist pin rotates in the aperture104.

In one embodiment, the anti-rotation wire lock208can be formed, for example, from chrome silicon and can have, for example, a finish of black oxide. However, the anti-rotation wire lock208can also be formed from other materials and have other finishes that are suitable for use in a piston. Also, the anti-rotation wire lock208can have a hardness of RC 52-54. However, the anti-rotation wire lock208can have any hardness which would render it suitable for use in a piston. In one embodiment, the ends of the anti-rotation wire lock208are deburred. In yet another embodiment, the entire anti-rotation wire lock can be deburred.

FIG. 3Aillustrates a perspective view of the anti-rotation wire lock208according to an example embodiment. As shown inFIG. 3A, the wire lock body216curls from the first end212toward a bend218. The second end214is connected to the wire lock body216by the bend218and extends in a direction out of a plane defined by the wire lock body216.

This relationship is further illustrated inFIG. 3B, which depicts a side view of the anti-rotation wire lock208. In particular, the second end214extends along a plane x that is out of a plane y defined by the wire lock body216. In the embodiment ofFIG. 3B, the second end214extends in a direction substantially perpendicular to plane y. Accordingly, in this example embodiment, angle θ inFIG. 3Bis approximately 90 degrees. In addition, the second end214extends from the wire lock body216along plane x by a distance B. In one example embodiment, the distance B can be within a range of 0.10 to 0.16 inches. However, it is understood that the second end214can protrude from the anti-rotation wire lock body216by any other suitable length so that the anti-rotation wire lock208can rest in the pick lock notch110.

FIG. 3Cillustrates a front view of the anti-rotation wire lock208depicting a diameter D and opening C of the wire lock body216. As will be appreciated by those of ordinary skill in the art, diameter D and opening C vary based upon the dimensions of the wrist pin lock groove in which the anti-rotation wire lock208is to rest. Similarly, diameter d of second end214varies based upon the dimensions of the pick lock notch in which the anti-rotation wire lock208is to rest. In one example embodiment, for example, the diameter d can be within a range of 0.0615 to 0.0635 inches. In yet another embodiment, diameter d can be within a range of 0.935 to 0.955 inches.

Although the second end214is on the left side of the opening C inFIG. 3C, it is understood that in other embodiments, the second end214and the first end212can be switched such that the second end214appears on the right side of opening C. This concept can be better understood by comparing the anti-rotation wire lock208ofFIGS. 2 to 6with the anti-rotation wire lock209ofFIGS. 7 to 10.

As shown in the top view ofFIG. 3D, the second end214defines an angle φ between plane x and a plane z, which is horizontal to the top surface of the wire lock body216. In this example embodiment, angle φ is approximately 90 degrees, however, angle φ can vary without departing from the spirit and scope of the present invention. For example, in one embodiment, angle φ can be within a range of 60 degrees to 130 degrees and still rest in the pick lock notch110to provide rotational resistance. In other embodiments, the second end214can curl or have a circular shape while being able to fit into the pick lock notch110and provide rotational resistance.

By reducing the rotation of the anti-rotation wire lock208, the wear and tear of the wrist pin lock groove106is substantially reduced or eliminated. This can ordinarily increase the longevity of the piston200and in some instances, allow for the piston200to operate at higher levels resulting in greater performance. In addition, the orientation of second end214to wire lock body216also facilitates easy insertion and removal of the anti-rotation wire lock208, as discussed below.

FIG. 4illustrates an exploded view of a piston assembly300when inserting the anti-rotation wire lock208into the wrist pin lock groove106of piston body102. Before inserting the anti-rotation wire lock208, the wrist pin112is inserted into the aperture104. The wrist pin112is temporarily held in aperture104using a clip114that fits into a wrist pin lock groove107on the opposite side of the anti-rotation wire lock208, as shown inFIG. 8.

InFIG. 4, the anti-rotation wire lock208is inserted using a first embodiment of a wire lock tool. As shown inFIG. 4, wire lock tool220includes a shaft222having an insertion end224and a removal end226. The insertion end224can be used, for example, to insert the anti-rotation wire lock208, while the removal end226can be used, for example, to remove the anti-rotation wire lock208. Both the insertion end224and the removal end226have an outside surface that is tapered so as to provide easier access and movement of the anti-rotation wire lock208when it is positioned in the wrist pin lock groove. In addition, both the insertion end224and the removal end226of the present embodiment are rounded at their ends to further reduce the likelihood of scratching piston200.

Wire lock tool220optionally includes a removable handle228which is constructed to fit onto the removal end226and a middle portion of the shaft222when the wire lock tool220is in a configuration for inserting the anti-rotation wire lock208. Similarly, the handle228is also constructed to fit onto the insertion end224and a middle portion of the shaft222when the wire lock tool220is in a configuration for removing the anti-rotation wire lock208.

As shown inFIG. 4, the insertion end224defines a through hole230which is constructed to mate with the first end212of the anti-rotation wire lock208. In the embodiment ofFIG. 4, the through hole230is substantially perpendicular to a longitudinal axis defined by the shaft222. Opposite the insertion end224, the removal end226defines a blind hole232which is constructed to mate with the second end214of the anti-rotation wire lock208. In this regard, the blind hole232of the present embodiment is substantially parallel to a longitudinal axis defined by the shaft222.

FIG. 5illustrates insertion of the anti-rotation wire lock208using the wire lock tool220without the removable handle228attached to the shaft222. As shown inFIG. 5, to insert the anti-rotation wire lock208, the second end214of the anti-rotation wire lock208is placed in the pick lock notch110. The first end212is then secured in through hole230of the wire lock tool220. By rotating the first end212in a direction234towards the second end214, the anti-rotation wire lock208can be semi-deformed, temporarily reducing the diameter of the anti-rotation wire lock208. This temporary deformation of the anti-rotation wire lock208results from the rotational resistance provided by the second end214when resting in the pick lock notch110. The anti-rotation wire lock208can then be slipped into the wrist pin lock groove106. Once the anti-rotation wire lock208is substantially in the wrist pin lock groove106, the first end212can be rotated in an opposite direction of the direction234to increase the diameter of the anti-rotation wire lock208and allow for removal of the first end212from through hole230.

FIG. 6illustrates removal of the anti-rotation wire lock208using the wire lock tool220without the removable handle228attached to the shaft222. As shown inFIG. 6, to remove the anti-rotation wire lock208, the shaft222of wire lock tool220is placed such that the second end214of the anti-rotation wire lock208is secured in blind hole232. In this configuration, the second end214of anti-rotation wire lock208provides leverage for removing the anti-rotation wire lock208from the wrist pin lock groove106. By rotating the second end214in a direction236towards the first end212, the anti-rotation wire lock208can be semi-deformed, temporarily reducing the diameter of the anti-rotation wire lock208. The anti-rotation wire lock208can then be slipped out of the wrist pin lock groove106and removed. Once the anti-rotation wire lock208is substantially out of the wrist pin lock groove106, the diameter of the anti-rotation wire lock208will ordinarily increase as it returns to its normal shape.

As will be appreciated by those of ordinary skill in the art, the directions234and236for insertion and removal are merely opposite directions from each other. For example, if direction236is clockwise, then direction234is counter-clockwise, and vice-versa. The respective directions for insertion and removal depend upon the sides of opening C (shown inFIG. 3C) that are chosen for the second end214and the first end212. This can be better understood by comparing the anti-rotation wire lock208ofFIG. 4with the anti-rotation wire lock209ofFIG. 7.

FIG. 7illustrates an exploded view of piston assembly300when inserting an anti-rotation wire lock209into the wrist pin lock groove106of piston body102. As withFIG. 4, before inserting the anti-rotation wire lock209, the wrist pin112is inserted into the aperture104. The wrist pin112is temporarily held in aperture104using a clip114that fits into a wrist pin lock groove107on the opposite side of the anti-rotation wire lock209, as shown inFIG. 8.

InFIG. 7, the anti-rotation wire lock209is inserted using a second embodiment of a wire lock tool. As shown inFIG. 7, wire lock tool240includes a shaft242and a handle246. The shaft242includes a taper244for added strength and a blind hole248for mating with the second end214of the anti-rotation wire lock209. The blind hole248is substantially parallel to an axis defined by the shaft242. In addition, the shaft242can have a rounded end near the blind hole240to further reduce the likelihood of scratching the piston200.

FIG. 8illustrates a rear perspective view of insertion of the anti-rotation wire lock209using the wire lock tool240. As shown inFIG. 8, clip114is temporarily inserted into the wrist pin lock groove107after the wrist pin has been inserted into aperture104. In this configuration, the wrist pin is ordinarily prevented from sliding out of aperture104while the anti-rotation wire lock209is inserted on the opposite side of the piston102. After the first anti-rotation wire lock is completely inserted, clip114can be removed for insertion of a second anti-rotation wire lock into wrist pin lock groove107.

FIG. 9Adepicts an initial positioning of anti-rotation wire lock209during insertion with wire lock tool240. The first end212of the anti-rotation wire lock209is placed in the wrist pin lock groove106close to, if not in, pick lock notch110. The shaft242of wire lock tool240is placed such that the second end214of the anti-rotation wire lock is secured in blind hole248.

As shown inFIG. 9B, the anti-rotation wire lock209is then compressed towards the center of aperture104until the anti-rotation wire lock209slides into the wrist pin lock groove106. If the second end214of the anti-rotation wire lock209is not already resting in pick lock notch110, the anti-rotation wire lock209is rotated towards pick lock notch110until the second end214is positioned in pick lock notch110, as shown inFIG. 9C. In the present embodiment, and as seen inFIGS. 9C and 10A, the end portion of shaft242fits into pick lock notch110for easy insertion and removal.

FIGS. 10A and 10Billustrate removal of the anti-rotation wire lock209from the wrist pin lock groove106using wire lock tool240. InFIG. 10A, an end portion of shaft242is placed in pick lock notch110such that the second end214of the anti-rotation wire lock209is secured in blind hole248of the wire lock tool240. The handle246of the wire lock tool240is then moved in the general direction indicated by the arrow inFIG. 10Ato pop the anti-rotation wire lock209out of the wrist pin lock groove106. In this sense, the second end214of anti-rotation wire lock209provides leverage for removing the anti-rotation wire lock209from the wrist pin lock groove106.

The handle246is then rotated in the general direction indicated by the arrow inFIG. 10B. As a result, the second end214of the anti-rotation wire lock209is rotated in a direction towards the first end212and the anti-rotation wire lock209is semi-deformed, temporarily reducing the diameter of the anti-rotation wire lock209. The anti-rotation wire lock209can then be slipped out of the wrist pin lock groove106and removed. Once the anti-rotation wire lock209is substantially out of the wrist pin lock groove106, the diameter of the anti-rotation wire lock209will ordinarily increase as it returns to its normal shape.

Thus, the above described use of wire lock tools in combination with the anti-rotation wire locks of the present disclosure allows for an easy insertion and an easy removal of an anti-rotation wire lock. This can ordinarily prevent damage to piston200, and more specifically, to the wrist pin lock groove106.