Abstract:
An engine component incorporates an installation feature for minimizing probability of misassembly of the component to or within an engine structure. For example, a ventless thermostatic valve may be made distinguishable from a vented, but otherwise identical, thermostatic valve, via the provision of tabs extending upwardly from the top of the ventless thermostatic valve. The tabs may be received into a corresponding tab-receiving groove of an associated engine part. As such, the tabs of the ventless component may offer a tactically sensitive distinguishing feature to signal that something may be amiss during an engine installation. The corresponding tab-receiving groove may be a widened aperture within a radiator elbow sleeve into which an upper portion of the ventless thermostatic valve may be mated and secured between an elbow sleeve flange and a cylinder head. Finally, a method of using the installation feature to reduce opportunities for misassembly error is disclosed.

Description:
TECHNICAL FIELD 
     An engine component installation feature and method may be employed to minimize probability of error during an engine assembly process. More particularly, the disclosure offers an apparatus and method for distinguishing between two substantially similar parts to reduce the potential of inadvertent misinstallation of similar but incorrect parts, including thermostatic valves, within engine structures such as cylinder heads. 
     BACKGROUND 
     While varieties of available machines, including front wheel loaders, excavators, road graders, milling machines, and the like, have become legion, the engines required to power such machines have become increasingly sophisticated and complex. As such, internal components required to build the engines have become more management intensive. By way of example, various parts employed in such machines may have different characteristics, such as operating conditions and ranges, even though the visual appearances of such parts may have only slight or subtle distinctions. 
     As one specific example, a thermostatic valve may include a small and nearly inconspicuous vent, while another thermostatic valve may be designed without such vent. Indeed the latter may be operationally suited and hence properly functional to prevent the overcooling of a newer or different engine. Accordingly, the installation of the vented thermostatic valve in an engine application requiring a ventless thermostatic valve, or vice versa, could lead to undesirable operation of the engine. Among various choices for avoiding misinstallation error, the obvious, such as color changes and/or changes in component sizing, may not always be practical. In addition, issues associated with mounting of and/or the securement of various components within engines may dictate uses of substantially standardized parts to the maximum possible extent. 
     U.S. Pat. No. 4,982,704 discloses a vehicle thermostat adapted for placement within the opening of an outlet housing. The outlet housing includes a positioning feature for assuring proper orientation of the thermostat within the opening of the outlet housing; the outlet housing has a slot, while the thermostat housing has a corresponding tab structure adapted for engagement with the slot. As such, the &#39;704 patent addresses only angular orientation of one part with respect to another. 
     Accordingly, it may be beneficial to provide an apparatus and method for avoiding unintended installation of a first component in place of a second similar and/or potentially confusing component within an engine exterior or interior, without necessity of making undue changes in their shapes and/or sizes to avoid misinstallation errors. 
     SUMMARY OF THE DISCLOSURE 
     In one disclosed embodiment, an installation feature may provide a tactically sensitive apparatus adapted to minimize probability of misassembly of an engine component to or within an engine structure. For example, a ventless thermostatic valve may be distinguishable from a vented, but otherwise identical, thermostatic valve via the provision of tabs that extend axially upwardly from the top of the ventless thermostatic valve. The tabs may be received in corresponding tab-receiving grooves, slots, or detents within a portion of an engine part adapted to be mated with the ventless component. For this purpose, a corresponding tab mating portion, for example a widened aperture in a radiator elbow sleeve into which, by way of further example, an upper portion of the ventless thermostatic valve may be mated, may be operable to secure the component between an elbow sleeve flange and a cylinder head. 
     In accordance with one aspect of the disclosure, an engine component may be installed under a specific protocol designed to avoid misapplication of, for example, an installation of a vented thermostatic valve where a ventless thermostatic valve should be installed. 
     In accordance with another aspect of the disclosure, the component may be oriented and positioned relative to one associated engine part prior to the installation of the resulting subassembly in an engine. 
     In accordance with a further aspect of the disclosure, the tabs and tab-receiving grooves may together provide an installation distinguishing feature to be utilized on one of two components for error avoidance, for example, for the inadvertent misinstallation of one component over the other. 
     In accordance with a further aspect of the disclosure, a method of error avoidance may include the association of a tab structure on one of two components and a grooved tab-receiving structure on an engine part with which the tabbed component may be associated, the association assuring that the tabbed component will be less likely mated to an incorrect engine part. 
     In accordance with a still further aspect of the disclosure, an installation distinguishing apparatus for one of two substantially similar components may include a plurality of tabs, and the tab-receiving groove of an associated engine part may extend 360° about the periphery of a flange on the associated engine part. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a prior art engine cylinder head that may incorporate an engine component according to the present disclosure. 
         FIG. 2  is a perspective view of a portion of the same engine cylinder head, but including a cutaway to reveal an area of the cylinder head that may incorporate an engine component according to the present disclosure. 
         FIG. 3  is a cross-sectional elevation view of a prior art engine component, shown secured in place against a prior art elbow sleeve, that may be selectively replaceable with the as-disclosed engine component having an installation feature, and in accordance with a disclosed error avoidance method. 
         FIG. 4  is a perspective view of the upper portion of the prior art engine component of  FIG. 3 , but shown alone; i.e. apart from the elbow sleeve, to reveal specific structure. 
         FIG. 4A  is a perspective view of a selected (encircled) portion of  FIG. 4 . 
         FIG. 5  is a cross-sectional elevation view of an engine component having the disclosed installation feature, shown mated to an as-disclosed modified elbow sleeve. 
         FIG. 6  is a perspective view of the modified elbow sleeve. 
         FIG. 7  is a perspective view of a shoulder ring, in accordance with another embodiment. 
         FIG. 8  is a perspective view of a modified elbow sleeve, in accordance with another embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     A typical internal combustion engine (not shown) may be used to supply motive power to a machine. The engine may generally include an array of elongated bores, called cylinders, as well as pistons (neither shown) that move reciprocally, albeit linearly, within the cylinders. The pistons are attached to a crankshaft (not shown) adapted to convert the linear motion of the pistons into rotary motion, as may be employed to rotate a machine driveshaft. Spark plugs (not shown) may be employed to sequentially burn an oxygenated combustible, i.e. a fuel, to create the piston movements. Alternatively, as for example in a diesel engine, heat of compression created by movement of the pistons, rather than spark plugs, may be sufficient to produce combustion for piston movement. In any event, the combustion process generates heat that may be transferred to and carried away by a coolant fluid. The fluid may be conveyed by a pump to a radiator (not shown) for appropriate cooling and return to the engine, as will be appreciated by those skilled in this art. 
     Referring to  FIG. 1 , an engine structure such as a cylinder head  10 , conventionally situated immediately above the pistons, is shown without a cover, to reveal an engine water cooling subassembly  12 . During a typical engine assembly process, various parts are assembled in sequence. Such parts include those of the subassembly  12 . 
     Referring now also to  FIG. 2 , a cutaway portion of the subassembly  12  reveals an engine component, for example a thermostatic valve  14  as shown, which during assembly of an engine may be inserted prior to installation thereover of a cooling conduit such as an elbow sleeve  16 . As such, the elbow sleeve  16  may fit over the thermostatic valve  14 , and a flange  18  of the elbow sleeve  16  may then be secured to the cylinder head  10 , over the thermostatic valve  14 , as further described below. 
     Referring now also to  FIG. 3 , the thermostatic valve  14 , shown oriented along an axis “a-a”, may incorporate a water temperature sensitive wax element (not shown), along with a spring  22  which may be effective to move and open a valve whenever the wax element has been sufficiently heated, as will be well known to those skilled in the art. The prior art housing  20  includes a top flange  30 . The flange  30  is effectively trapped between an upper mating surface  32  of the cylinder head  10  and a bottom flange  18  of the elbow sleeve  16 , although a rubber seal  46  may be physically interposed between the top flange  30  and the mating surface  32 , as will be appreciated by those skilled in the art. Typically such rubber seal  46  may be part of the assembled structure of the thermostatic valve  14 . Alternatively such seal  46  may be a separately installed part. 
     Bolts  34  extend through apertures  26  of the flange  18 , the bolts  34  having threaded shafts  36  that extend into the mating surface  32  for direct threaded securement to the cylinder head  10 , as shown. Washers  38  may be interposed between the bolts  34  and the elbow sleeve flange  18  to aid in achievement of proper torquing of the bolts with respect to the flange  18  and the mating surface  32  of the cylinder head  10 . Those skilled in the art will also appreciate that an annular exterior ridge  24  may be effective for the later securement of a rubber hose (not shown) that may extend between the engine cylinder head  10  and a radiator (not shown). 
       FIG. 4  depicts a view of the thermostatic valve  14  that reveals the top flange  30  that may define an upper extremity of the housing  20 , as described above. Referring now also to  FIG. 4A , a vent  40  is defined by an aperture that may be included in the prior art thermostatic valve  14 , the vent being situated in an upper portion of the housing  20 . The vent  40  may allow a small amount of coolant to flow into the radiator (not shown) even when the thermostatic valve  14  may be in the “closed” position. Such a coolant flow may help to avoid an otherwise potentially deleterious thermal shock to the radiator that might arise from the opening of the thermostatic valve  14  after the coolant has reached a predetermined temperature. In some applications, however, the small amount of coolant flow through the vent  40  is enough to undesirably delay (or even prevent) sufficient warming of coolant in the engine, as for example when ambient air may be extremely cold, e.g. minus 20 C, and the engine may be operating at relatively low RPM&#39;s. The vent  40  may lead to excessive cooling, and hence deleterious performance or even failure issues. 
     As such, referring now to  FIG. 5 , a ventless thermostatic valve  14 ′, may be oriented along an axis “b-b” upon its installation within the cylinder head  10 , and may provide an alternative structure for engines having operating characteristics that call for use of ventless thermostatic valves, e.g. to prevent issues of excessive cooling in certain applications. The ventless thermostatic valve  14 ′ may be both operationally and physically identical in all respects to the prior art thermostatic valve  14 , except for inclusion of the vent  40  of the prior art thermostatic valve  14 . Indeed, the thermostatic valves  14  and  14 ′ may be visually similar in overall design and appearance, including size, color, and shape, such as the elongated shape disclosed. 
     In order to reduce potential misassembly of the two engine components, i.e. the respective thermostatic valves  14  and  14 ′, an installation feature such as a pair of upstanding tabs  50  may be formed as a modified top flange  30 ′ in the ventless thermostatic valve  14 ′, as shown. To accommodate the tabs, a modified elbow sleeve  16 ′ may contain a flange  18 ′ that includes a widened shoulder, as may be defined by a recessed groove  54 , adapted to receive the tabs  50 . As shown, the tabs may extend upwardly, parallel to axis b-b, but may have other viable orientations as well within the scope of this disclosure. The tabs  50  may be embodied by other structures that provide a protrusive installation feature adapted to be mated only with the flange  18 ′ having a recessed groove  54 , and hence to prevent assembly with a flange  18 . As such, the protrusive installation feature may instead be a raised shoulder ring  60 , as shown in  FIG. 7 , that extends entirely about the top flange  30 ′ of the valve  14 ′, by way of just one example. 
     Referring now to  FIG. 6 , a perspective view of the groove  54  within the modified flange  18 ′ of the modified elbow sleeve  16 ′ depicts a 360° circumferential recessed portion. Although the groove  54  is thus shown to extend entirely about the sleeve  16 ′, the groove  54 ′ may alternately be segmented as shown in  FIG. 8 , may extend less than 360°, and/or may otherwise be adapted to accommodate the tabs  50 . However, it may be appreciated by those skilled in the art that the 360° circumferential extent of the groove  54  may permit a greater amount of flexibility with respect to angular positioning of the flange  18 ′ over the cylinder head mating surface  32  during assembly. 
     Finally, a specific process or method adapted to utilize the above-described tab and groove engine component installation features will be specifically detailed below. 
     INDUSTRIAL APPLICABILITY 
     The disclosed installation distinguishing feature may be adapted for reducing the potential selection of and misassembly of one engine component over another component, such as the installation of thermostatic valve  14  over a thermostatic valve  14 ′, for example. The installation feature may thus be beneficial in the assembly of engines for a variety of machines, including wheel loaders, excavators, tractors, trucks, and other off-road machines. As disclosed herein, the described installation feature may be used to avoid potentially damaging consequences of operating engines containing misassembled parts. 
     A method for ensuring that substantially visually similar engine components, such as thermostatic valves  14  and  14 ′, are not misassembled, i.e. and by way of example, in a situation wherein a vented thermostatic valve  14  is utilized, but wherein a ventless thermostatic valve  14 ′ should have been used, may now be particularly described as follows. 
     Referring back to  FIG. 3 , a prior art vented thermostatic valve  14  may contain a top flange  30  as previously described; i.e. without tabs  50 . A standard elbow sleeve  16  containing a standard ungrooved flange  18  may be paired with the vented thermostatic valve  14 , and both components may be associated with an engine requiring the vented thermostatic valve. Conversely, referring now back to  FIG. 5 , a ventless thermostatic valve  14 ′ may contain a modified top flange  30 ′, containing at least a pair of the upstanding tabs  50 . The thermostatic valve  14 ′ may be paired with a sleeve  16 ′ that contains a modified flange  18 ′, in turn containing the recessed groove  54 , as shown. 
     Those skilled in the art will appreciate that the use of two modified parts reduces the statistical risk of mistakes over the use of only a single modified part. As such, the thermostatic valve  14 ′ along with the sleeve  16 ′ may be correspondingly associated with an engine requiring a ventless thermostatic valve, so as to avoid overcooling of the latter engine of the type requiring a ventless thermostatic valve  14 ′. 
     A protocol may be set up for managing such respective engine components, and in particular to keep them separately arranged for appropriate use by engine assembly workers. Thus, an engine component installation method for reducing probability of misinstallation of apparently similar albeit different first and second engine components within first and second engines having different operating characteristics may be described as follows: 
     a) providing an engine component installation distinguishing feature on a first engine component to differentiate the first engine component from a second engine component; 
     b) identifying and modifying a part to be secured to the first engine component to accommodate the installation feature of the first engine component, wherein the first engine component and the modified part define a first subassembly; 
     c) identifying an unmodified part to be secured to the second engine component, wherein the second engine component and its unmodified part define a second subassembly; 
     d) associating the first and second engine subassemblies with one of the first and second engines, respectively; and 
     e) providing a system for managing pluralities of first and second engine subassemblies, including keeping the respective subassemblies apart from one another prior to and during respective first and second engine assembly processes. 
     Such a component management protocol may effectively achieve the intended result, i.e. avoiding misassembly of one component when another component is called for. In the event, however, of a mis-association, i.e. if a tabbed thermostatic valve  14 ′ may be attempted to be used with a standard elbow sleeve  16 , the assembler will receive immediate tactile feedback as an indication of a misassembly problem, since the upstanding tabs  50  will directly interfere with efforts to secure the bolts  34  that extend through the flange  18  of the standard or unmodified elbow sleeve  16 . As such, the assembler will be unable to properly secure the bolts  34  through the flange  18  for effective securement thereof against the mating surface  32  of the cylinder head  10 . As such, the assembler may thus receive instant notice of undesirable interference. 
     Finally, even if such interference is missed by an engine assembler during an engine assembly, a subsequent leak test may be effective to reveal the misassembly issue, to the extent that the bolts  34  will have been unable to effectively secure the flange  18  against the mating surface  32  in a leak-proof fashion. While a vented valve  14  may be mated with the flange  18 ′ as a misassembly, with the vented valve being assembled to a non-vented engine, such a failure would not necessarily lead to major issues. Conversely, however, the opposite type of mis-assembly, i.e. a non-vented valve  14 ′ being mated to an engine that requires a vent, may be problematic. The latter potential misassembly may be effectively prevented by the apparatus of this disclosure.