Abstract:
A continuous flow regulator for vehicle heating systems includes a body configured to be connected in-line with coolant flowing through the heating coil of the heating system. A spring biased ball valve assembly is disposed in the body and is configured to restrict flow through the regulator in response to increasing flow rate of coolant and to open flow through the regulator in response to decreasing flow rate of coolant. Flow rate of coolant is therefore continuously adjusted and regulated to protect the heater core from corrosion due to high coolant flows therethrough.

Description:
REFERENCE TO RELATED APPLICATION 
     Priority is hereby claimed to the filing date of U.S. provisional patent application No. 61/505,712 filed on 8 Jul. 2011. 
    
    
     TECHNICAL FIELD 
     This disclosure relates generally to vehicle heating systems and more particularly to protection of vehicle heater cores from damage due to excessive flow of coolant through the cores. 
     BACKGROUND 
     A typical vehicle heating system includes a heater core through which hot coolant from the vehicle&#39;s engine circulates to heat the core. Air is blown through fins of the core, which heats the air. The heated air is then expelled into the passenger compartment of the vehicle to provide heating. 
     Heater cores can deteriorate over time and require replacement. Deterioration can be caused at least in part by high pressure and high volume flows of coolant through the core. High flows, for example, can exacerbate abrasion of interior tubing of the core by particles entrained in the flows, and can cause cavitation damage particularly at bends in the tubing where cavitation can occur. There exists a need to regulate the flow of coolant through vehicle heater cores to reduce deterioration and thus expand the lives of the cores. It is to the satisfaction of this need that the present disclosure is primarily directed. 
     SUMMARY 
     Briefly described, a continuous flow regulator, in the form of a heater barb in the preferred embodiment, is disposed in-line with a heater hose delivering coolant to the heater core of a vehicle. Alternatively, the regulator may be disposed in-line with the heater hose receiving coolant from the heater core of a vehicle after the coolant has circulated through the core. Coolant circulating through the heater core is thus constrained to flow through the regulator prior to entering the heater core or after leaving the heater core. The regulator has a body with an internal passageway bounded by a generally cylindrical interior wall. A set of tapered ribs projects inwardly from the interior wall toward the axis of the channel. A ball valve assembly comprising a spherical ball and a biasing spring is disposed within the internal passageway. The ball is biased by the spring to an upstream position that provides maximum flow around the ball and through the regulator. If coolant flow exceeds a predetermined rate, the ball is moved by the flow toward the downstream end of the regulator and against the bias of the spring. This movement progressively reduces the space between the ball and the inwardly projecting tapered ribs. Accordingly, flow of coolant through the regulator and to the heater core is restricted and reduced. The ball valve assembly responds continuously in this manner to varying coolant flow rate, thereby ensuring that the heater core receives a substantially constant flow of coolant at a regulated flow rate that reduces deterioration of the core. A filter can be incorporated into the regulator if desired to entrap particulates entrained in the flow thereby reducing core deterioration through abrasion. These and other aspects, features, and advantages of the flow regulator and method of this disclosure will be better appreciated upon review of the detailed description set forth below taken in conjunction with the accompanying drawing figures, which are briefly described as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective exploded view of the flow regulator of this disclosure illustrating principle components thereof. 
         FIG. 2  is a longitudinal cross section of the flow regulator in its assembled condition illustrating the ball valve assembly. 
         FIG. 3  is an end view of the regulator of this disclosure in its assembled condition. 
         FIG. 4  is a perspective cross sectional view of the flow regulator in its assembled condition. 
         FIG. 5  is a perspective cross sectional view of the flow regulator as seen from the upstream end thereof. 
     
    
    
     DETAILED DESCRIPTION 
     The entire contents of U.S. provisional patent application 61/505,712, to which priority is claimed above, is hereby incorporated by reference. 
     Reference will now be made to the drawing figures, wherein like reference numerals indicate like parts throughout the several views. The description that follows will reference all of the drawing figures as a group, except where an individual figure is singled out. 
     As illustrated in the figures, a flow regulator  11  comprises an outer body  1  having a nipple  12 , which, in this embodiment, is configured as a heater barb, at its downstream end for connection to a heater hose. The outer body  1  has an internal channel bounded and defined by an interior wall  21 . The interior wall  21  at the pstream end of the outer body  1  is radially stepped to form internal seats  13  and  14 . An inner body  2  has a barrel  16  at its downstream end and a flange  17  at its upstream end. The barrel  16  and flange  17  are separated by a radial step  15  extending around the inner body  2 . The inner body  2  terminates at its upstream end in a radially extending end flange  18 . A generally cylindrical central channel extends through the inner body  2  and is bounded by generally cylindrical wall  22 . A set of four inwardly projecting tapered ribs extend radially inwardly from the cylindrical wall  22  and each rib tappers from a narrow dimension at the upstream end of the inner body  2  to a wide dimension at the downstream end of the inner body  2 . 
     A ball valve assembly  7  ( FIG. 5 ) is disposed within the central channel of the inner body  2  and comprises a cylindrical ball  3  and a coil spring  4 . As perhaps best illustrated in  FIG. 2 , one end of the coil spring is wedged between the ribs  19  at the downstream end of the inner body  2  and the cylindrical ball  3  is fixed to the other end of the coil spring so that the ball is located at the upstream end of the inner body  2 . It will thus be appreciated that the cylindrical ball is yieldably biased by the coil spring to the position shown in  FIG. 2  but can be forced to move in a downstream direction against the bias of the spring by a sufficient force from the left in  FIG. 2 . Significantly, as the cylindrical ball moves in the downstream direction, the spaces between the surface of the ball and the inner surfaces of the ribs  19  are progressively narrowed. This continues until the cylindrical ball itself contacts the inwardly projecting ribs and can move no further in the downstream direction. 
     In operation, the regulator is connected in-line with a heater hose. This may be the hose that feeds hot coolant to a heater coil of a vehicle&#39;s heater system. In this case, the regulator is attached at the upstream side of the heater coil before coolant enters the coil. Alternatively, the regulator may be connected in-line with the heater hose that delivers coolant from the heater coil back to the engine or coolant reservoir, in which case it is attached at the downstream side of the heater coil after coolant leaves the heater coil. In either case, the regulator is oriented so that the flow of coolant is directed from the upstream end of the regulator to the downstream end of the regulator as illustrated by the “FLOW” arrow in  FIG. 4 . 
     As hot coolant flows through the heater coil, it must pass through the regulator either as the coolant enters the coil or as the coolant leaves the coil. The coolant flowing through the regulator imparts a force on the cylindrical ball  3  of the ball valve assembly  7  in the downstream direction. This, in turn, forces the ball  3  to move in the downstream direction against the bias of the coil spring  4 . The magnitude of the movement, and thus the position of the cylindrical ball in the inner channel  22 , is proportional to the, amount of force imparted to the ball, which, in turn, is proportional to the flow rate of coolant through the regulator. As flow rate increases, the ball is moved more toward the downstream end of the regulator and as flow rate decreases, the ball is urged by the coil spring back toward the upstream end of the regulator. 
     When the ball moves toward the downstream end of the regulator, the spaces or gaps between its surface and the tapered ribs  19  becomes progressively narrower. Accordingly, the total open area presented to the flow is progressively reduced. At some point, the ball contacts the ribs (or the spring collapses completely), which closes the gaps to their smallest sizes and presents a minimum open area to the flow that defines a desired regulated flow or flow rate. Conversely, as the ball moves toward the upstream end of the regulator, the gaps between the surface of the ball and the surfaces of the tapered ribs widens, thereby presenting a progressively larger open area to coolant flowing through the regulator. It will thus be understood by those of skill in the art that higher flow rates and pressures of coolant result in a more restricted flow path through the regulator thereby reducing the speed of the flow. Lower flow rates of coolants result in a less restricted flow path through the regulator thereby increasing the flow. This automatic and continuous reaction to flow rate and consequent pressure constantly adjusts to changes in flow rate with the end result that the flow rate is regulated continuously to be within a predetermined desired preferably narrow range. The range is selected to be one that is less destructive to heater cores while still providing sufficient continuous flow for the heater to operate effectively. It has been found that sizing the ribs and the cylindrical ball such that the regulator will allow a flow rate that is about 120-150 percent of the desired regulated flow rate when the ball is biased completely toward the upstream end of the regulator provides good regulation. Further, a filter (not shown) such as a thimble filter for instance may be incorporated into the regulator at, for example, the upstream end of the outer body  1  to trap particulate and other abrasive materials that may become entrained in the flow of coolant. This enhances even more the protection of a heater core provided by the regulator of this disclosure. 
     The invention has been disclosed in terms and within the context of preferred embodiments and methodologies considered by the inventor to represent the best mode of carrying out the invention. It will be appreciated, however, that a wide range of additions, deletions, and modifications might be made to the preferred embodiments presented herein without departing from the spirit and scope of the invention as set forth in the claims.