Patent Document

BACKGROUND OF THE INVENTION. 
     1. Field of the Invention 
     The invention pertains to assembly fixtures for properly positioning internal combustion engine rocker arm pedestals prior to the pedestals being bolted to engine structure. 
     2. Description of the Related Art 
     While fixtures for positioning elements prior to final assembly with another component are known, the need for a low cost fixture for positioning rocker arm pedestals in an internal combustion engine has long existed. Because of the complexity of the configuration and shape of an engine inlet manifold, it has been very difficult to provide a fixture which would accurately hold rocker arm pedestals in position prior to the pedestals being bolted to the engine structure. Prior attempts to utilize an assembly fixture for rocker arm pedestals have not been universally acceptable, and prior to the advent of the instant invention, considerable time and expense has been wasted in the difficulty of properly positioning rocker arm pedestals prior to assembly. 
     OBJECTS OF THE INVENTION. 
     It is an object of the invention to provide a fixture for the positioning of rocker arm pedestals in an internal combustion engine prior to the pedestals being bolted to the engine structure. 
     Yet another object of the invention is to provide a fixture for positioning rocker arm pedestals which firmly holds the pedestals within the fixture during handling of the fixture, and wherein the fixture does not interfere with the mounting of the pedestals in the engine. 
     An additional object of the invention is to provide a rocker arm pedestal fixture which is of a molded configuration having a shape which corresponds to the engine inlet manifold and wherein the fixture configuration readily “nests” within the engine components to permit the assembler to recognize proper alignment between the pedestals and their mounting holes. 
     A further object of the invention is to provide an assembly fixture for internal combustion engine rocker arm pedestals which is molded of a low cost temperature resistant synthetic material which may remain in the engine without adverse effect. 
     SUMMARY OF THE INVENTION. 
     An internal combustion engine rocker arm fixture in accord with the invention consists of an elongated molded body of a complex configuration. The body is preferably molded of a temperature resistant synthetic material, such as a glass fiber reinforced resin, and is capable of withstanding the temperatures exteriorly encountered with an automotive internal combustion engine without significant degradation. 
     The fixture body includes a lower side which is configured to cooperate with the shape of the engine inlet manifold so that the fixture will firmly rest upon the engine surfaces adjacent the location where the rocker arm pedestals are mounted. Further, the fixture body includes recesses or rests which provide clearance for the engine push rods and springs, and further aid in positioning of the fixture within the engine. 
     The body consists of a plurality of enlargements or islands interconnected by relatively thin bridges forming a relatively rigid structure. A rectangular recess is defined within each of the islands adapted to snugly receive a rocker arm pedestal. Each of the recesses is provided with means for holding a pedestal within the recess consisting of a resilient finger having a barb on its free end adapted to cooperate with a shoulder defined on the pedestal. Vertical positioning of the pedestal within the recess is determined by a pair of projections formed on opposite sides of the recess which engage locating surfaces formed in notches defined on the pedestals. In this manner, the fingers and projections prevent the pedestals from being removed from the associated recess, and the snug relationship between the recess and the pedestals assures that the pedestals will be properly located within the recesses, and the fixture. 
     After the rocker arm pedestals have been inserted within all of the fixture recesses, the pedestals, usually six in number, and the fixture are placed within the engine and properly located by the configuration of the fixture relative to the engine components, and the pedestals can be quickly firmly attached to the engine structure by the usual bolts extending through the pedestal countersunk bores. 
     The configuration of the fixture, and its composition, permits all of the fixture components to be homogeneously molded in one operation at low cost, and the relationship of the fixture to the pedestals is such that the fixture may remain in place within the engine during normal engine operation without interfering in any way with engine function. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein: 
     FIG. 1 is a perspective view of an internal combustion engine rocker arm pedestal fixture in accord with the invention, 
     FIG. 2 is a plan view of the fixture, 
     FIG. 3 is an elevational side view of the fixture as taken from the bottom of FIG. 2, 
     FIG. 4 is an enlarged detail elevational sectional view as taken through a fixture recess along Section  4 — 4  of FIG. 2, and 
     FIG. 5 is a perspective view of an internal combustion engine inlet manifold illustrating a fixture in accord with the invention in position with the rocker arm pedestals within the fixture. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The overall configuration of the rocker arm assembly fixture is best apparent from FIGS. 1-3 wherein the configuration of the fixture  10  will be appreciated. The fixture  10  consists of a molded body  12  having ends  14 , lateral sides  16  and  18 , a top surface  20  and a bottom surface  22 . 
     Preferably, the body  12  is molded of a synthetic relatively rigid heat resistant material such as glass fiber reinforced resin. 
     As will be appreciated from FIG. 3, the body  12  does not lie in a single plane but is contoured to accommodate the configuration of the internal combustion engine intake chamber or manifold in which it will be mounted, as later described, and while the body bottom surface  22  basically consists of a series of flat surface portions, these portions are not co-planar as will be apparent from FIG.  3 . 
     The body  12  includes a plurality of enlarged portions or islands  24  intermediate its ends, and outer island  26  are located at the ends of the body and are of a larger configuration than the inner islands  24 . Adjacent islands are interconnected by homogeneous bridges  28 , and sufficient material exists within the bridges, and the thickness of the body  12  is such, that the entire body  12  is rigid and capable of maintaining dimensional and contoured integrity. 
     Each of the islands  24  and  26  includes a rectangular recess  30  in which a rocker arm pedestal will be mounted, as later described. The recesses  30  include opposed planar parallel sides  32 , and the other opposed recessed sides each include a well  34 , as best apparent in FIG.  4 . Each of the wells  34  includes an upstanding cantilevered finger  36  whose free upper end includes a barb  38 , FIG. 4, having a lower flat surface. Also, each of the wells  34  includes a projection  40  extending into the associated recess  30  to aid in the vertical positioning of the pedestals, as later described. 
     At each of the islands  24  and  26 , on body side  16 , a push rod rest or cradle  42  is defined for accommodating the engine push rods, and each of the outer islands  26  is provided with a spring rest or cradle  44  defined on body side  18  to provide accommodation for the engine valve springs, as later described. 
     A typical rocker arm pedestal  46  with which the fixture  10  of the invention is used is shown in dotted lines in FIG. 4, and appears in full lines in FIG.  5 . The upper surface of the pedestal  46  is of a concave configuration to accommodate the bearing structure of the rocker arm, and the pedestal includes an internal bore  47  which is countersunk to provide an internal shoulder permitting a screw, not shown, to be inserted through the bore and the screw head will engage upon the bore shoulder. 
     Adjacent its lower end, the pedestal  46  is provided with a pair of notches  48 , and at approximately one-half its height, the pedestal  46  includes a notch defining a ledge  50 . The pedestal  46  also includes opposite parallel sides  52  which are spaced apart a distance only slightly less than the distance separating the recess sides  32  whereby the insertion of the pedestal within the recesses  30  such that the sides  52  engage the recess sides  32  results in a snug fit of the pedestals within the recesses  30 . 
     The internal combustion engine with which the invention is used is shown at  54  in FIG.  5 . The illustrated engine represents one bank of a V-6 cylinder engine. The engine includes push rods  56  and a pair of valve springs  58  are associated with each cylinder. For purposes of illustration, much of the rocker arm structure required with the engine  54  is not shown. Such rocker arm structure being mounted upon the pedestals  46  as is well known. 
     In use, a rocker arm pedestal  46  is located within each recess  30 . The pedestals  46  are inserted through the top surface  20  of body  12  and the configuration of the free outer ends of the fingers  36  is such as to permit the pedestals to temporarily deform the fingers  36  away from the pedestals permitting the pedestals to be received within the associated recess. Upon the pedestal being sufficiently inserted into its recess, the pedestal notch  48  will engage the body projection  40  preventing further insertion of the pedestal into the recess, and at such time, the finger barbs  38  will spring inwardly to overlie the ledges  50  defined upon the pedestals. Accordingly, in this manner, the pedestals  46  will be firmly “locked” within the body recesses  30 , and the assembled fixture  10  and pedestals  46  can be handled and stored as a unit. 
     When it is desired to install the pedestals  46  within the engine  54 , the body  12  and pedestal  46  assembly is located within the engine intake manifold in a manner apparent from FIG.  5 . Because of the configuration of the body lower surface  22 , the operator can feel when the body  12  is properly located within the engine intake manifold, the engine push rods  56  will be within the push rod rests  42 , and the outer tension springs  58  will be located within the body spring rest  44 . When the fixture  10  is so located, the pedestal bores  47  will be aligned with the threaded bores in the engine  54 , not shown, adapted to receive the pedestal bolts which are inserted through the pedestal bores  47  and tightened to firmly mount the pedestals individually upon the engine. 
     After the bolts extending through the pedestals  46  are firmly tightened, the pedestals will be properly located upon the engine, and the fixture  10  performs no further purpose. However, because the fixture  10  is molded of a temperature resistant material, the fixture can remain within the engine intake manifold and in no way interferes with the engine operation. 
     It will be appreciated that the fixture  10  permits the pedestals  46  to be quickly and accurately located within the engine  54  for assembly purposes substantially reducing the assembly time, and reducing the likelihood of assembly error, and the low cost of the molded fixture  10 , although only used once, is significantly less than the labor and time saved. 
     It is appreciated that various modifications to the inventive concepts may be apparent to those skilled in the art without departing from the spirit and scope of the invention.

Technology Category: 2