Patent Publication Number: US-6901992-B2

Title: Fastenerless mounting bracket for heat exchangers

Description:
TECHNICAL FIELD 
   This invention relates to automotive air conditioning in general, and specifically to a novel design for automotive heat exchanger mounting and support brackets. 
   BACKGROUND OF THE INVENTION 
   Automotive heat exchangers comprise a basic central core comprised of regularly spaced tubes and intermediate corrugated air fins, framed on four sides by a pair of parallel header tanks. Although this invention is intended for any similar heat exchanger it has particular utility with a condenser. Typically, the condenser header tanks are vertically oriented, and the tubes horizontally oriented. Some means is necessary to mount to condenser physically to the vehicle, generally in front of the engine-cooling radiator. The condenser may be mounted directly to the vehicle frame, or indirectly mounted to the vehicle by mounting to the radiator. Whether it&#39;s directly or indirectly mounted to the vehicle, the condenser generally requires several brackets, securely fixed to its core structure, which can in turn receive threaded bolts or other fasteners to allow the condenser to be fixed in place. 
   The alternatives for providing mounting brackets on the condenser include extruding the header tank with integral rails, or attaching separate brackets. Integral rails are heavy, being the full length of the extruded tank, an example of which may be seen in U.S. Pat. No. 5,671,803. Much of the weight of an extruded header tank rail can be processed away in a post extrusion manufacturing step, leaving only a discrete flange, but the extra step adds expense. Most separate mounting brackets are metal pieces that are somehow fixed to the header tank before the brazing operation and then brazed on solidly later. Numerous examples may be seen in the prior art, as in U.S. Pat. No. 5,205,349. The addition of discrete, localized metal masses to an otherwise regular metal part is undesirable in that it can introduce irregularities in the braze temperature profile, as well as interfere with the smooth stacking and running of parts on the conveyor belt. Separate mounting brackets may also be attached after the brazing operation, as shown in U.S. Pat. No. 5,535,819, where metal brackets are bolted to the condenser reinforcement after the braze operation. One or more fasteners are needed for each of four brackets, which involves considerably more labor than simply snapping a bracket to a header tank prior to the braze operation. One recent U.S. Pat. No. 6,202,737, shows a condenser attached to a radiator tank with a bracket that is described as being “nested” on top of the condenser tank before being snapped to the radiator tank. It is unclear what “nesting” means, and unclear what material is used in the bracket. Yet another development is disclosed in U.S. Pat. No. 6,513,579, wherein a plastic mounting bracket that is press fit onto each corner of the condenser addresses some of these problems. These plastic brackets are simple and light molded pieces that are attached to the corners of condenser core entirely post braze, in a simple press fit operation that needs no separate fasteners. Each bracket has a cap that fits closely over the end of header tank and an integral channel on the side that snap fits over the core reinforcement, with no additional fasteners needed. Once installed to the condenser core, the plastic brackets gain solid twisting resistance from both sides of the condenser corner, as well as solid removal resistance from the close, snap fit. There remains a need for simple and effective mounting arrangements for heat exchangers that avoid the use of fasteners and accommodate brazing and processing of the heat exchanger core. 
   SUMMARY OF THE INVENTION AND ADVANTAGES 
   The subject invention provides a unique mounting system for a heat exchanger assembly comprising a heat exchanger core having opposite faces surrounded by ends and sides with a first header manifold disposed at one side of the heat exchanger core and a second header manifold  30  in parallel relationship to the first header manifold and disposed along the other side of the heat exchanger core. Each of said manifolds has a constant cross section along the length thereof and at least one projection disposed along the first manifold. A plastic bracket grips the first manifold and includes at least one recess disposed about the projection for preventing the bracket from moving along the manifold. 
   The subject invention allows the use of a plastic bracket in combination with a header manifold of simple cross section without rails or extensions whereby the manifold may be extruded, made in a tube mill, or the like, in a continuous and constant cross section. The bracket is attached without the use of any fasteners. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
       FIG. 1  is a perspective view of a first embodiment of the invention; 
       FIG. 2  is a cross sectional view taken along line  2 — 2  of  FIG. 1 ; 
       FIG. 3  is a cross sectional view taken along line  3 — 3  of  FIG. 1 ; 
       FIG. 4  is a close-up view of  FIG. 3 ; 
       FIG. 5  is perspective view of the heat exchanger core without the bracket attached thereto; 
       FIG. 6  is perspective view of the bracket only; 
       FIG. 7  is a frontal view of a heat exchanger assembly incorporating a second embodiment of the bracket; 
       FIG. 8  is perspective view of the second embodiment of the bracket shown in the closed position; and 
       FIG. 9  is perspective view of the second embodiment of the bracket shown in the open position. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to the drawings wherein like numerals indicate like or corresponding parts throughout the several views, an automotive heat exchanger or condenser assembly is generally indicated at  20 . The heat exchanger assembly  20  comprises a heat exchanger core  22  having opposite faces surrounded by ends  24  and sides  26 , the core  22  being of the well known type including tubes and fins. A first header manifold  28  is disposed at one side  26  of the heat exchanger core  22  and a second header manifold  30  is in parallel relationship to the first header manifold  28  and is disposed along the other side of the heat exchanger core  22 . As is well known in the art, the core  22  includes tubes for conveying fluid between the manifolds  28  and  30 ,  28  and  30  and fins on the tubes for effective heat transfer. Each of the manifolds  28  and  30  has a constant cross section along the length thereof. More specifically, the cross section is circuitous or endless, as in a circle or oval. Each manifold  28  and  30  has a transverse dimension (A) perpendicular to the faces of the heat exchanger core  22  which is larger than the distance (B) between the faces of the core  22 . 
   A plurality of projections  32  are disposed along each of the manifolds  28  and  30 . The projections  32  take the form of beads formed in the pipe defining the manifolds  28  and  30  or collars, rings or separator ears added prior to brazing. Alternatively, the projections can project inwardly to define grooves or valleys. In yet another alternative, locating ears as part of the separator could be used. 
   A plastic bracket, generally indicated at  34  in  FIGS. 1-6  and at  134  in  FIGS. 7-9 , is in gripping engagement with each of the first manifold  28  and the second manifold  30 . The bracket  34  and  134  includes a plurality of recesses  36  disposed about the projection  32  for preventing the bracket  34  and  134  from moving along the associated manifold  28  or  30 . The brackets  34  or  134  on opposite sides of the core  22  are mirror images of one another for oppositely gripping the first  28  and second  30  manifolds. Alternatively, the two halves could be identical with the two halves oriented 180° relative to one another. The brackets are integrally molded or one piece plastic components. The design shown in  FIGS. 8 &amp; 9  could also be in two pieces instead of being connected by a living hinge. 
   Each bracket  34  and  134  includes a pocket  38  surrounding the associated manifold  28  or  30  and a pair of spaced flanges  40  extending from the pocket  38  to engage the faces of the heat exchanger core  22 . The cross section of each manifold  28  and  30  is round and the pocket  38  is complementary to that roundness shape. The flanges  40  have inside surfaces engaging the faces of the heat exchanger core  22  that are closer together at the distance (B) than the transverse dimension or diameter (A) of the manifolds  28  and  30  for retaining the bracket  34  and  134  on the heat exchanger core  22  and to prevent rotation of the bracket, about the axis of the manifold. In other words, the flanges  40  are closer together (B) than the inside diameter (A) of the pocket  38  in the bracket  34 . In the case where the projections  32  extend radially inwardly to define a groove instead of radially outwardly, the recesses  36  would be an inwardly extending duration or rib disposed in the groove. 
   As will be appreciated the projections  32 , whether they be male or female (out or in), define irregularities and the recesses  36 , whether they be male or female, define deviations complimentary to one another for locking engagement to prevent longitudinal movement of the bracket  34  along the manifold. Of course, the manifolds  28  and  30  could have other than a circular cross-section. 
   A support tab  42  extends from the pocket  38  in the opposite direction from the flanges  40  for mounting the bracket  28  or  30  to a support structure of a vehicle. 
   The bracket  34  of  FIGS. 1-6  differs from the bracket  134  of  FIGS. 6-9  in that the first embodiment  34  snaps onto the manifold  28  or  30  and is held in place by the frictional clamping forces of the stationary flanges  40  thereof whereas the flanges  40  of the second embodiment are hinged by a living hinge  44  to rotate into clamping engagement with the manifold  28  or  30 . As alluded to above, the living hinge could be replaced by a hinge between separate parts, even identical parts. To accommodate the placement of the bracket  34  onto the manifold  28  or  30 , the recesses  36  include extensions  46  that extend into the flanges  40  for receiving the projections  32  as the flanges  40  of the bracket  34  separate in sliding over the manifold  28  or  30 . In addition, the distal ends of the flanges  40  include outwardly extending flares  48  for facilitating movement of the manifold  28  or  30  into the pocket  38 . The first bracket  34  also includes cutouts  50  along the flanges  40 . In order to facilitate or simplify molding, the cutouts being staggered along the flanges so that a cutout does not face another cutout, i.e., each cutout is disposed opposite to a flange  40 . 
   As alluded to above, the second embodiment of the bracket shown at  134  in  FIGS. 7-9  includes a living hinge  44  to move the flanges  40  thereof in a circular path about the axis of the hinge  44  and into clamping engagement with the opposite faces of the core  22  with the pocket  38  thereof engaging the associated manifold  28  or  30 . In order to hold the bracket  134  in the clamping position, a plurality of snap posts  52  extending for one flange  40  have hooked ends that snap into latch holes  54  in the other flange  40 . The posts extend through guides  56  in the clamped or locked position, as shown in FIG.  8 . The posts  52  extend through openings in the core  22 . 
   Obviously, many modifications and variations of the present invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described within the scope of the appended claims.