Abstract:
A coolant reservoir for an internal combustion engine is made from two plastic molded sections, an upper one of which is formed with an integral inlet/syphon tube that extends downwardly into the reservoir when the sections are assembled together to provide a conduit through which coolant can enter the reservoir and syphon from the reservoir without the need for a separate tube.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims benefit from U.S. provisional applications Nos. 61/287,907 filed Dec. 18, 2009 and 61/364,188 filed Jul. 14, 2010 which are incorporated herein by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to coolant reservoirs for internal combustion engines. 
       BACKGROUND OF THE INVENTION 
       [0003]    A coolant reservoir functions by providing a volume into which hot engine coolant can migrate as the coolant expands. The reservoir is connected to the engine cooling system with hoses so that the coolant can flow to the reservoir as the coolant expands and return to the cooling system as it cools and contracts. Typically, the reservoir is fitted with a syphon tube which provides an inlet from the engine cooling system and a return path to the cooling system. In extreme cases, the coolant may overflow the reservoir through an overflow outlet, from which it can be directed to another location by way of a hose. 
         [0004]    Typically, hoses are connected to fluid reservoirs at defined points to address specific functions. The hoses and attachment points create unique concerns, increased costs and possible leak points, as well as taking up space and increasing manufacturing costs and/or difficulties. 
         [0005]    The practice of integrating features into a molded part has been undertaken in the past in order to reduce manufacturing cost and shipping cost arising from a reduced number of components. For example, a tube may be integrated on the exterior of a blow molded component to reduce the length of the hose that has to be connected to the component. Molded features such as barbed outward projections are a routine means for attaching a tube or hose to a reservoir. 
         [0006]    The following references were considered in the preparation of this application:
   U.S. Pat. No. 7,552,839 (Padget)   U.S. Pat. No. 3,741,172 (Andreux)   U.S. Pat. No. 7,188,588 (Hewkin)   U.S. Pat. No. 4,480,598 (Berrigan)   U.S. Pat. No. 4,738,228 (Jenz, et al.)   
 
       SUMMARY OF THE INVENTION 
       [0012]    According to one aspect of the invention there is provided a coolant reservoir for an internal combustion engine having a cooling system, the reservoir comprising at least two plastic molded sections that are sealed together to define an internal volume for receiving coolant. The reservoir has an inlet for connection to the engine cooling system and an outlet providing an overflow. The inlet is defined by an syphon tube that extends downwardly from one of the molded sections into the internal volume, terminating adjacent to but spaced from a bottom wall of reservoir. At least a portion of the syphon tube is molded integrally with the one molded section and extends both into and outwardly of the reservoir, the syphon tube opening to the exterior of the reservoir through the one molded section. 
         [0013]    In summary, at least a portion of the syphon tube is integrated into, normally, an upper section of the reservoir, in effect becoming a detail formation on that section. In most cases, there will be two plastic molded sections, namely the upper section and a lower section and the two sections will meet and be sealed together in a horizontal plane that extends through the reservoir. As such, when the two sections are assembled together, at least a portion of the inlet/inlet tube is already formed on the upper molded section and the reservoir is completed in one assembly step. 
         [0014]    It has been found that a molded reservoir section with an integral inlet/syphon tube can readily be made by injection molding. In some cases, it may not be practical to mold the entire syphon tube in one piece with the reservoir section. For example, it may be practical difficulties with tooling if the height of the reservoir exceeds a certain level. It such a situation, the integrally molded portion of the syphon tube will extend a certain distance into the internal volume of the reservoir and an extension tube will be added, with or without a clamp, to bring the syphon tube to the required overall length. 
         [0015]    The overflow outlet from the reservoir may be formed in the same way as the inlet/syphon tube and may or may not include a tubular portion that protrudes inwardly of the reservoir. An outlet of this form may be used on a reservoir with a conventional inlet. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings which illustrate a number of preferred embodiments of the invention by way of example, and in which: 
           [0017]      FIG. 1  is a vertical sectional view through a coolant reservoir in accordance with one aspect of the present invention; 
           [0018]      FIG. 2  is a detail view of the left hand portion of the reservoir showing the inlet/syphon tube; 
           [0019]      FIG. 3  illustrates a modification of  FIG. 2  using a shorter syphon tube; 
           [0020]      FIG. 4  is a view similar to  FIGS. 2 and 3  illustrating an alternative form of inlet/syphon tube; 
           [0021]      FIG. 5  is a perspective view of the portion of the upper molded section of the reservoir of  FIG. 4 , in the vicinity of the inlet/syphon tube; 
           [0022]      FIG. 6  is a perspective view of a coolant reservoir in accordance with a further aspect of the invention; 
           [0023]      FIG. 7  is an exploded, detail view of the reservoir showing the inlet/syphon tube; 
           [0024]      FIG. 8  is a vertical sectional view on line A-A of  FIG. 6 ; 
           [0025]      FIG. 9  is a view similar to  FIG. 7  illustrating an alternative form of inlet/syphon tube; and, 
           [0026]      FIG. 10  is a view similar to  FIG. 8  illustrating the inlet/syphon tube of  FIG. 9 . 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0027]    Referring first to  FIG. 1 , a coolant reservoir in accordance with the invention is generally designated by reference number  20  and is shown to include upper and lower molded sections  22  and  24  respectively that meet in a horizontal plane P of the reservoir. The two sections are formed with mating outwardly protruding flanges  22   a  and  24   a  respectively at which the two sections are welded or otherwise sealed together. The reservoir has an inlet/syphon tube generally indicated at  26  for connection to the engine cooling system, and an overflow outlet  28 . A cap on the reservoir is not visible. 
         [0028]    Referring now more particularly to  FIG. 2 , it can be seen that the inlet/syphon tube  26  is formed integrally as part of the upper molded section  20  and includes a portion  26   a  that extends downwardly to a location adjacent a bottom wall  30  of the reservoir, formed by part of the lower molded section  24 . The inlet/outlet tube also includes a portion  26   b  that extends outwardly of the reservoir and opens to the exterior of the reservoir, through the upper molded section. 
         [0029]    As the temperature of coolant in the engine cooling system increases, coolant will eventually flow through the inlet portion  26   b  and into the reservoir. When the temperature of the coolant drops sufficiently, coolant will return to the engine cooling system by way of the syphon provided by the inlet/syphon tube  26 . 
         [0030]      FIG. 3  is a view similar to  FIG. 2  showing a shorter syphon, formed by a “core out” in the upper molded section indicated in dotted lines at  32 . 
         [0031]      FIGS. 4 and 5  show a similar configuration of the upper reservoir section but in which the inlet/syphon tube is replaced by a plain tube  26 ′ that extends vertically through a wall portion of the upper housing part both outwardly and inwardly of the reservoir as best seen in  FIG. 4 . Tube  26 ′ is molded integrally with the upper housing part  22 . 
         [0032]    As mentioned previously, the reservoir also includes an outlet/overflow  28  that provides a safety feature for the extreme case in which the reservoir becomes completely filled by coolant. The outlet overflow  28  is also integrally formed as part of the upper reservoir housing section  20 . During the injection molding process, a nozzle  28   a  is formed as part of the outlet  28 . The outlet may also include a portion  28   b  indicated in broken lines, that extends inwardly of the reservoir. In some systems, slosh is a concern. Portion  28   b  may address that concern by acting as a baffle. Additional baffle elements or other functional features may be added to address specific design requirements. 
         [0033]    Reference will now be made to  FIGS. 6 to 10  of the drawings, which illustrate a form of coolant reservoir that has a significantly greater overall height than the reservoir shown in  FIGS. 1 to 5 . As noted previously, in situations such as this, it may be difficult to mold an inlet/syphon tube in one piece with the upper molded section of the reservoir. 
         [0034]    Primed reference numerals are used in  FIGS. 6 to 8  to denote parts that correspond with parts shown in  FIGS. 1 to 5 . 
         [0035]    The reservoir in  FIGS. 6 to 10  is generally square in plan view and (as noted previously) is taller than the reservoir shown in the previous views. A cap on the reservoir is indicated at  41 . In this embodiment, a portion only of the syphon tube is molded integrally with the upper molded section of the reservoir and extends both into and outwardly of the reservoir. The length of the syphon tube is extended beyond the integrally molded part  26   a  that extends into the reservoir by a syphon tube extension  42 . 
         [0036]    As shown in  FIG. 8 , extension  42  is a push fit over portion  26   a  of the syphon tube. 
         [0037]    The embodiment shown in  FIGS. 9 and 10  is essentially the same as the embodiment of  FIGS. 6 to 8  except that the syphon tube is positively held in place on inlet tube portion  26   a  by means of a screw clamp  43 . 
         [0038]    It will be appreciated that the preceding description relates to particular preferred embodiments of the invention and that numerous modifications are possible within the broad scope of the invention. Some of those modifications have been indicated previously and others will be apparent to a person skilled in the art. 
         [0039]    In the illustrated embodiments, the integrally molded syphon tube or portion thereof extends down from the upper one of the two plastic molded sections. While in general that may be the preferred configuration, it would be possible for the syphon tube to be molded integrally with the lower housing section. For example, in the embodiment of  FIG. 3 , the plane between the upper and lower molded sections could lie in the vicinity of the core out  32 , below the top wall of the reservoir, in which case, the inlet/syphon tube would be integrally molded with the lower housing section.