Patent Publication Number: US-6334375-B1

Title: Tool for engine crank shaft

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to crankshafts and more particularly, to a tool for an engine crankshaft pulley designed to hold the crankshaft pulley stationary while installing or removing the crankshaft sprocket bolt. 
     2. Description of the Related Art 
     A frequently encountered problem when attempting to remove or install the crankshaft sprocket bolt is that the crankshaft pulley rotates when a torque is applied to the crankshaft sprocket bolt making it difficult to either loosen or tighten the crankshaft sprocket bolt. For the crankshaft sprocket bolt to be readily loosened or tightened, it is required that the crankshaft pulley remain stationary as a torque is applied to the crankshaft sprocket bolt because the rotation of the crankshaft pulley prevents an adequate torque from being applied to the crankshaft sprocket bolt. However, the work space involved is very restricted, therefore, the auto mechanic has very little room in which to work, which severely limits the number of viable options available to the auto mechanic for holding the crankshaft pulley stationary. 
     The prior art describes a variety of implements used to facilitate the installation and removal of various automotive components. U.S. Pat. No. 4,580,446 issued on Apr. 8, 1986 to J. J. Ansteth describes a degree wheel and a method of using the degree wheel. The novel degree wheel is adjustably mounted to the crankshaft. The degree wheel is mounted to a bushing by a threaded nut that is loosened or tightened as desired. The wheel can be easily adjusted so that a zero degree reading corresponds to a top dead center of piston travel. The degree wheel includes counterclockwise 0 degree to 360 degree indicia for a direct and calculation-free determination of the duration of tappet lift. 
     An engine crankshaft indexing method and tool is described in U.S. Pat. No. 4,922,749 issued on May 8, 1990 to T. J. Steffes. The crankshaft rotation tool and method facilitates tests and the making of repair adjustments requiring precise indexing of the degrees of the crankshaft rotation. The tool engages and imparts rotation to existing bolts that mount an existing pulley to the crankshaft. 
     U.S. Pat. No. 5,257,556 issued on Nov. 2, 1993 to R. P. Pineault describes a torque technique and apparatus. The tool which produces a measured torque is coupled to a bolt head or nut located in a relatively inaccessible area by an apparatus which includes a wrench member affixed to an adaptor. The wrench member is sized and shaped to engage the fastener to be operated upon and the adaptor has a tubular construction with a tool engaging socket at one end. The adaptor is provided with an elongated slot which accommodates any wires which may pass through the fastener. 
     None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a tool for preventing engine crank shaft rotation when installing or removing the crankshaft sprocket bolt, thus solving the aforementioned problems, is desired. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a principal object of the invention to provide a tool that facilitates the removal and installation of a crankshaft sprocket bolt. 
     It is another object of the invention to provide a tool that prevents crankshaft rotation when installing and removing a crankshaft sprocket bolt. 
     It is a further object of the invention to provide a tool that prevents crankshaft rotation when installing and removing a crankshaft sprocket bolt which may be used where working space is confined so that the crankshaft sprocket bolt may be removed while the engine is still in the engine compartment of the vehicle. 
     Still another object of the invention is to provide a tool for preventing rotation of the crankshaft during crankshaft sprocket bolt removal that is sturdy and durable. 
     It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
     The foregoing objectives are achieved in accordance with the present invention by providing a tool that facilitates the removal and installation of the crankshaft sprocket bolt. The implement of the present invention is installed on the crankshaft pulley and holds the crankshaft pulley stationary as a torque is applied to the crankshaft sprocket bolt by a mechanic using a wrench. The operational end of a breaker bar is inserted into an appropriately configured opening in the tool to hold the tool and crankshaft pulley stationary as a wrench applies a torque to the crankshaft sprocket bolt to either loosen the sprocket bolt for removal or to tighten the sprocket bolt during installation of the sprocket bolt. 
     The tool of the present invention eliminates the possibility of accidentally damaging the fly wheel, pulleys, belts, and timing plate on the timing belt cover while removing or installing the crankshaft sprocket bolt. The solid construction of the tool of the present invention provides the mechanic with a sturdy and durable implement that can endure the rigors of frequent and repeated use. The innovative contour of the tool allows the implement to be quickly and easily installed and removed from the crankshaft pulley. The tool of the present invention eliminates the possibility of damage to the engine as a result of inadvertent rotation of the crankshaft while removing or installing the crankshaft sprocket bolt. 
     In a first embodiment, the tool has a two piece construction with a detachable upper portion and an exchangeable lower portion. The two piece construction allows a user to interchange the upper portion with lower portions of different configurations adapted to fit crankshaft pulleys of different sizes. In a second embodiment, the tool has a one piece construction that is less expensive to manufacture. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an environmental, perspective view of a first embodiment of the tool in use according to the present invention. 
     FIG. 2 is an environmental, perspective view of a crankshaft pulley with the assembled tool installed. 
     FIG. 3 is a perspective view of the assembled tool with the breaker bar installed. 
     FIG. 4 is a perspective view of the assembled tool and a breaker bar. 
     FIG. 5 is a perspective view of the assembled tool. 
     FIG. 6 is an exploded view of the tool showing the two piece construction of the tool. 
     FIG. 7 is a top view of the assembled tool. 
     FIG. 8 is a bottom view of the assembled tool. 
     FIG. 9 is a perspective view of the base plate portion of the tool. 
     FIG. 10 is a perspective view of the top portion of the tool. 
     FIG. 11 is a perspective view of a second embodiment of the tool having a single, one piece construction. 
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention, as depicted in FIGS. 1-11, is a tool  100  that allows a mechanic to readily remove the crankshaft sprocket bolt  112 . The implement  100  of the present invention prevents the crankshaft shaft pulley  114  from rotating as a torque is applied to the crankshaft sprocket bolt  112  as shown in FIG.  1 . FIG. 1 is an environmental, perspective view of a first embodiment of the tool  100  in use. The tool  100  is mounted onto the crankshaft pulley  114  with three of the four crankshaft pulley bolts  120  disposed within the grooves or recesses  116  defined in the baseplate portion  104  of the tool  100 . With a breaker bar  122  in one hand and a wrench  124  in the other hand, a mechanic using the wrench  124  applies a torque to the crankshaft sprocket bolt  112  while holding the tool  100  stationary using the breaker bar  122  as shown in FIG.  1 . As a torque is applied to the crankshaft sprocket bolt  112  using a wrench  124 , the crankshaft pulley  114  is prevented from rotating in the direction of the applied torque by the pulley bolts  120  engaging the baseplate portion  104  of the tool  100  which is held in place by the breaker bar  122 . 
     FIG. 2 is an environmental, perspective view of a crankshaft pulley  114  with the assembled tool  100  installed showing how the tool  100  is sized to fit neatly over three of the crankshaft pulley bolts  120 . The recesses  116  of the baseplate portion  104  of the tool  100  are sized to accommodate the heads of the crankshaft pulley bolts  120  employed. FIG. 3 is a perspective view of the assembled tool  100  with the breaker bar  122  installed showing how the drive  126  of the breaker bar  122  fits snugly and securely into the square drive hole  108 . The shape of the drive opening  108  (see FIG. 2) can be changed to accommodate the needs of the user. FIG. 4 is a perspective view of the assembled tool  100  with a disengaged breaker bar  122 . 
     FIG. 5 is a perspective view of the assembled tool  100  showing the distinctive contour of the tool  100 . FIG. 6 is an exploded view of the tool  100  showing the two piece construction of the first embodiment of the tool  100 . The two piece embodiment of the tool  100  consists of a flat, detachable, arcuate top plate  102  that has a medially disposed ½ inch square hole  108  defined in a boss  110  that protrudes downward when the top or upper plate  102  of the tool  100  is oriented as shown in FIG. 5 and a pair of laterally disposed dowel pins  106  that also extend downward as shown in FIG.  6 . Although the hole  108  and boss  110  are preferably square to accept the more commonly used square drive breaker bars, it will be understood that the hole  108  may be hexagonal, octagonal, or other polygonal shape to accommodate the less commonly used hexagonal or octagonal drive tools. 
     The removable baseplate or bottom portion  104  of the tool  100  also has a flat, arcuate shape. The baseplate  104  of the tool  100  has a ¾ inch square opening  130  that is disposed slightly eccentrically as shown in FIG.  6 . In addition, the baseplate  104  has a pair of openings or holes  118  to accommodate the dowel pins  106  of the upper portion  102  of the tool  100  and a set of three recesses  116  to accommodate the bolts  120  of the crankshaft pulley  114 . The three recesses  116  can be configured to fit the contour or shape of the crankshaft pulley bolts  120 . The primary purpose of the ¾ inch square aperture  130  and dowel pins holes  106  is to allow bottom plates  104  of different designs to be attached to the top portion  102 . The bottom plate  104  depicted in the first embodiment of the tool  100  is for a crankshaft pulley  114  with four bolts  120 . As shown in FIG. 6, each recess has opposing faces spaced apart a predetermined distance for engaging the opposing faces of a crankshaft pulley bolt  120  in order to prevent rotation of the bolt  120 . 
     FIG. 7 is a top view of the assembled tool  100  and FIG. 8 is a bottom view of the assembled tool  100 . Both figures show the novel configuration and innovative contour of the tool  100 . The contour and configuration of the tool  100  is especially designed to allow the tool  100  to conveniently and efficiently perform the task of preventing the crankshaft pulley  114  from rotating as a torque is applied to the crankshaft sprocket bolt  112 . The flat, arcuate shape of the top plate  102  and the baseplate  104  permit the tool  100  to be aligned parallel to the crankshaft pulley  114 , the concave opening defined by the tool  100  being sized and dimensioned for permitting the recesses  116  to engage the heads of at least three crankshaft pulley bolts  120 , so that the tool  100  may be thought of as the head of a wrench capable of engaging the heads of three bolts simultaneously to prevent rotation of the pulley. The top plate  102  and the baseplate  104  have sufficient thickness and strength to withstand the torque required to loosen or tighten the sprocket bolt  112 . 
     FIG. 9 is a perspective view of the baseplate portion  102  of the tool  100  showing the openings in the baseplate  102  into which the square drive boss  110  and the dowel pins  106  of the top portion  102  of the tool  100  are inserted. The openings in the baseplate  104  consists of a square hole  130  into which the square drive boss  110  fits and a pair of laterally disposed openings  118  into which the dowel pins  106  fit. In a preferred embodiment, the baseplate  104  has an outer diameter of 4 inches, an inner diameter of 1¾ inches, and a height of ¼ inches. The dowel pin holes have a depth of ¼ inches and the square hole  130  has a length of ¾ inches, a width of ¾ inches, and a height of ¼ inches. The recesses  116  have a length of ¾ inches, a height of ½ inches, and depth of ¼ inches. The recesses  116  are symmetrically disposed about the center  136  of the baseplate  104  so that the baseplate  104  can grip the pulley bolts  104  with a three-point or triangular grip. 
     FIG. 10 is a perspective view of the top plate  102  of the tool  100  oriented to show the square drive boss  110  and the laterally disposed dowel pins  118 . The square drive boss  110  has a raised appearance when viewed from the orientation of the tool  100  depicted in FIG.  10 . The square drive boss  110  and the laterally disposed dowel pins  118  fit into their corresponding openings in the baseplate portion  104  of the tool  100 . In a preferred embodiment, the top plate  102  of the tool  100  has an outer diameter of 4 inches and an inner diameter of 2½ inches. The dowel pins  106  have a diameter of ¼ inches and a length of ½ inches. The raised boss  110  has a length of ¾ inches, a width of ¾ inches, and a height of ¼ inches. The square drive hole  108  has a length ½ inches and width of ½ inches. The number of recesses  116  can be varied to meet the specific needs of the user. 
     FIG. 11 is a perspective view of a second embodiment of the tool  200 . The tool  200  depicted in FIG. 11 has a single, one piece construction with a configured upper part  138  and a configured lower part  140 . The tool  200  has a circular horseshoe shape and is open at one end as depicted in FIG.  11 . The closed end of the tool  200  has a ½ inch square hole  108  defined therein for receiving a ½ inch square drive. There are three grooves  116  in the bottom of the tool  200  that are oriented toward the geometric center  136  of the tool  200 . The grooves  116  are at right angles to each other. In a preferred embodiment, the tool  200  has a maximum thickness of ½ inches, an outer diameter of 4 inches, and an inner diameter of 1¾ inches. The two piece tool  100  has the same overall dimensions as the one piece tool  200 . The tool  100 , 200  can be made of any suitable material, for example, a steel alloy. 
     In order to enhance the utility of the tool, the top plate  102  of the two-piece tool  100 , or the entire one piece tool  200  may be magnetized. This causes the tool to adhere to the pulley by magnetic attraction so that the tool  100  or  200  doesn&#39;t slip or fall out of place while the mechanic is maneuvering for leverage to use the wrench  124  on the crankshaft bolt  112 , or is setting the wrench  124  aside to complete removal of the bolt  112  by hand, or wishes to maintain the tool  100  or  200  on the pulley while his other hand is engaged in other tasks. 
     The crankshaft pulley holding tool or implement of the present invention makes it easy for the mechanic to remove or install the crankshaft sprocket bolt. By inserting a ½ inch drive ratchet, breaker bar, or extension into the ½ inch square drive hole of the tool and placing the recesses of the tool over the shaft pulley bolts heads, the mechanic can prevent the crankshaft from turning and easily loosen or tighten the crankshaft sprocket bolt. The two piece tool with its changeable baseplate is designed to accommodate crankshafts of different sizes while the one piece too is less expensive to manufacture. The tool can be used by mechanics in repair facilities, military auto craft shops, service stations, technical institutes, and by individuals with mechanical skills. 
     The preferred embodiment of the present invention disclosed herein are intended to be illustrative only and are not intended to limit the scope of the invention. It should be understood by those skilled in the art that various modifications and adaptations of the present invention as well as alternative embodiments of the present invention may be contemplated. It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.