Abstract:
A damper is shown for damping the movements of a spring. The spring is housed within the damper. The side walls of the damper have inverted T-shaped cutouts and hinge members resulting in flexure of the side walls when the spring is compressed or released. A steel band can be housed on the outside surface of the side walls providing biasing of the inside of the side walls against the outside of the spring thereby damping movement of the spring.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Provisional application for Patent Ser. No. 60/794,801 filed on Apr. 25, 2006. 
    
    
     FIELD 
     The present versions of these embodiments relate generally to the field of dampers for springs and more particularly to the damping of valve springs in engines. While valve springs are specifically discussed, these dampers could be used for other applications such as suspension springs, fuel injector springs, clutch springs and others. 
     BACKGROUND 
     These embodiments relate to the field of dampers for springs, and more particularly to the damping of valve springs in engines. In order for four cycle internal combustion engines to run, there needs to be a way of allowing the fuel-air mixture into the combustion chamber. When the fuel-air mixture has been burned, then the exhausted fuel-air mixture and combustion products must exit the combustion chamber. This has been done in the background art by providing at least one valve per cylinder that opens and closes to allow the fuel-air mixture into the combustion chamber and traditionally at least one other valve per cylinder to allow the spent fuel-air mixture and combustion products to leave the combustion chamber. The valves traditionally have springs which interact with the valve and are provided typically with a rotating cam to depress and release the valve. 
     The valves are opened by having the cam pressing on the valve forcing the valve toward the combustion chamber thus opening the valve and compressing the valve spring. When the valve is released, the valve spring moves or returns the valve to the closed position. When the valve is opened the spring compresses and upon release of the valve, the spring returns the valve to the closed position. 
     This type of system works relatively well for most applications, but today with the smaller, higher revolution per minute (rpm) engines, the need for decreased weight in vehicles, the need for higher efficiency engines and other reasons, the current valve spring system is not as desirable. As these smaller engines are operated at higher rpms for longer periods of time, the valve springs do not have time to completely stop oscillating when the valve is fully engaged and when the valve is fully released. This oscillation of the valve springs can lead to leakage when the valve is released and decreased flow when the valve is engaged to allow fuel and air into the cylinder. The valves can also float or flutter, meaning that the valves are not operating as efficiently as would be desired. 
     One way to discourage the float or flutter is to get the valve and specifically the valve spring to stop oscillating when opened and closed. Once the valve is closed, in a perfect system, both the valve and spring would stop moving. Conversely, once the valve is opened, both the valve and spring would stop moving. This does not occur in the real world and the valve spring continues to move up and down, or oscillate, for a finite time period and then stops. It is desirable to have the spring stop moving as quickly as possible when compressed and also when released. 
     Much of the background art also uses a separate valve stem seal to discourage the lubricating oil from penetrating into the combustion chamber. It would be beneficial to have this valve stem seal incorporated into the spring damper to decrease manufacturing costs and also to ease assembly. 
     The damping of oscillations has traditionally been done by engineering the spring or spring materials to decrease this spring oscillation. Current engineering has approached the limit for damping these oscillations with spring engineering and spring materials. Some background art shows the use of dampers attached to the spring to lessen these oscillations. 
     A damper can be any material that will stop a spring from oscillating. Various embodiments have been developed to stop the spring from oscillating such as a dual spring system, installing a damper on the outside of the spring, installing a damper on the inside of the spring. Many of the current systems have significant disadvantages to them that do not allow the optimum damping of the valve springs. These systems can be costly and difficult to install and maintain and some require re-engineering the cam shafts and cylinder heads where the valves and valve springs are located. 
     For the foregoing reasons, there is a need for a spring damper that will discourage the spring from oscillating when the spring is compressed and released. 
     SUMMARY 
     In view of the foregoing disadvantages inherent in the level of the art in valve springs there is a need for a spring damper. 
     A first object of these embodiments is to provide a damper that is relatively cost effective to manufacture and install. 
     Another object of these embodiments is to provide a damper that will dampen the valve spring oscillations more effectively and efficiently than those currently available. 
     It is yet another object of these embodiments to provide a damper that will have a long life cycle and maintain damping performance over a longer time period with minimal wear or damage to the spring. 
     Another object of these embodiments is to provide a damper resulting in minimal wear to the spring surface and limited metal filings from spring wear which can then contaminate the lubrication system of the engine. 
     Another object of these embodiments is to provide a spring damper that incorporates a valve stem seal to simplify assembly and reduce costs. 
     It is a still further object of these embodiments is to provide a damper that can be installed without redesigning the valve spring, cylinder head or engine. 
     These together with other objects of these embodiments, along with various features of novelty which characterize these embodiments, are pointed out with particularity in the detailed description and forming a part of this disclosure. For a better understanding of these embodiments, their operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  shows a side cutaway view of one embodiment of a damper and stem seal along A-A of  FIG. 3   
         FIG. 2  shows a perspective view of one embodiment of the damper in FIGS.  1 , 3   
         FIG. 3  shows a top view of one embodiment of the damper of FIGS.  1 , 2 . 
         FIG. 4  shows a side cutaway view of one embodiment of a damper along B-B of  FIG. 6 . 
         FIG. 5  shows a perspective view of one embodiment of the damper in FIGS.  4 , 6 . 
         FIG. 6  shows a top view of one embodiment of the damper of FIGS.  4 , 5 . 
         FIG. 7  shows a side cutaway view of one embodiment of a damper along C-C of  FIG. 9 . 
         FIG. 8  shows a perspective view of one embodiment of the damper of FIGS.  7 , 9 , 10 . 
         FIG. 9  shows a top view of one embodiment of the damper of FIGS.  7 , 8 , 10 . 
         FIG. 10  shows another perspective view of one embodiment of the damper of FIGS.  7 , 8 , 9 . 
         FIG. 11  shows an exploded view of one embodiment of the damper. 
         FIG. 12  shows an exploded view of one embodiment of the damper with a modified stem seal. 
         FIG. 13  shows a perspective view of one embodiment of the damper alone. 
         FIG. 14  shows a side view of one embodiment of the damper without alone. 
         FIG. 15  shows another side view of one embodiment of the damper alone. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a cutaway view of a damper  18  of  FIG. 3  along line A-A. The damper  18  is generally cylindrical in shape, is made from steel sheet and houses spring S. One end of the spring S rests on the platform  20  of the damper  18  and the other end of spring S generally extends from the top  30  of damper  18 . The damper  18  has a central axis  40  with a stem housing  22  extending from the platform  20  toward the top edge  30  of the damper  18  and centered on the central axis  40 . The stem housing  22  is formed from a relatively rigid cylinder  26  extending from platform  20  and topped with a pliable seal  28 . The seal  28  seals against the valve stem (not shown) to prevent oil leakage. 
     The top  30  has a formed upper edge  32 . This upper edge  32  eases the assembly of spring S into damper  18 . Damper  18  is generally formed from with two side walls  34 . Each of the side walls  34  is connected to the platform  20  with a hinge member  36 . The width and angle of the hinge members  36  can be adjusted or changed to provide different properties to the flexure of the side walls  34  against the spring S. This provides a gap  38  between the side walls  34  and platform  20  such that side walls  34  essentially float in a position above the platform  20 . 
     The side walls  34  are also separated from one another by vertical spacings  41  which are approximately 180 degrees apart and parallel to central axis  40 . The edges of the sidewalls  34  at vertical spacing  41  are turned away from the central axis  40  providing vertical lips  44  on each end of vertical spacing  41 . 
     The vertical lips  44  are not present where the band  24  crosses over the vertical spacing  41 . In other words, vertical lips  44  are removed so that band  24  contacts the outer surface of the side walls  34 . Band  24  biases side walls  34  toward central axis  40  bending at hinge members  36 . Band  24  is located between the top  30  and bottom edge  35  of side walls  34 . When the side walls  34  are biased toward central axis  40 , the bottom edge  35  still maintains separation from platform  20  maintaining gap  38 . The band  24  can be manufactured from spring steel or other material with similar properties. 
     The hinge member  36  can vary in width thereby providing more or less flexure or movement of side walls  34  against spring S. The band  24  also provides bias to side walls  34  against spring S. When the damper  18 , band  24  and spring S are installed, the cycling of the spring S is damped by the side walls  34  contacting the outer surface of spring S as it compresses and decompresses. The spring S thus damps or ceases movement quicker than if no damper  18  and band  24  are installed. 
       FIGS. 13 ,  14 , and  15  show an isolated view of the damper alone.  FIG. 13  shows a perspective view of the damper  18  and can be seen one embodiment of the T-shaped slot having a vertical spacing  41  and gap  38  near the bottom. The hinges  36  are shown having a cutout  37  on each side of the hinges  36 . The two pair of vertical lips  44  can be seen near the top of the vertical spacing  41  and two pair of vertical lips  44  can be seen near the bottom of the vertical spacing  41 . 
       FIG. 4  shows a cutaway view of another embodiment of damper  18  and spring S along B-B in  FIG. 6 .  FIG. 5  shows a perspective view and  FIG. 6  shows a top view of damper  18  and spring S. 
     In this embodiment damper  18  has a top edge  30  with a formed upper edge  32  where upper edge  32  is bent away from central axis  40 . At the bottom of damper  18  is a platform  20 . A stem housing  22  is affixed to the platform  20  at one end and extends from platform  20  terminating at a position near the top edge  30 . The stem housing  22  is approximately centered on central axis  40 . The stem housing  22  can have a step  23  having a larger diameter than an attached cylinder  26 . The top of cylinder  26  is affixed to a seal  28  which seals the valve stem (not shown) sealing the lubricating oil from penetrating the seal  28  to possibly enter the combustion chamber (not shown). The seal  28  also aids in centering the spring S and Damper  18  relative to the valve stem (not shown). The bottom of cylinder  26  is attached to the step  23 . The step  23  is attached to the platform  20 . 
     The embodiment shown in  FIGS. 4 ,  5 ,  6  shows T shaped slots  46  (see  FIG. 5 ) approximately 180 degrees from one another in the side walls  34 . The slots  46  have a vertical component  47  extending from the top edge  30  toward the platform  20  terminating at the circumferential component  48 . Circumferential component  48  extends some pre-defined distance radially in the side wall  34  of damper  18 . The length of the vertical component  47  and circumferential component  48  effect the amount of flexure in the side walls  34  of the damper  18  and can be adjusted in position and length depending upon the design parameters of this embodiment of damper  18 . 
     FIGS.  7 , 8 , 9 , 10  show another embodiment of damper  18 .  FIG. 7  is a cutaway view of damper  18  and spring S along C-C of  FIG. 9 . In this embodiment of damper  18  there is only one hinge member  36 ,  FIGS. 9 ,  10 . Opposite hinge member  36  is a single vertical spacing  41  extending from the top edge  30  to the platform  20 . The edges or vertical lips  44  of vertical spacing  41  are bent away from central axis  40 . The hinge member  36  has on either side cutouts  37 , one shown in  FIG. 10 . The length of the hinge member  36  and the size of cut outs  37  can be varied and adjusted depending on the design parameters for damper  18 .  FIG. 7  also shows a gap  38  such that side wall  34  essentially floats over platform  20 . 
     Attached to platform  20  and centered on central axis  40  is step  23 . Attached to step  23  is cylinder  26  extending toward the top edge  30  of damper  18 . At the top of cylinder  26  is seal  28 . Seal  28  is used to seal the valve stem (not shown) as has been discussed prior. 
     The embodiment shown in FIGS.  7 , 8 , 9 , 10  differ from those of FIGS.  1 , 2 , 3  where only one hinge member  36  is used, and therefore there is only one vertical spacing  41  with corresponding vertical lips  44 . 
       FIG. 12  shows another embodiment of the damper  18 . In this embodiment, stem housing  22  is attached to step  23 . Step  223  has an upper lip  60  which is formed to interact with edge  62  of stem housing  22 . Stem housing  22  still has a seal  28  which is separately manufactured and affixed to the top of cylinder  26 . The stem housing  22  is then inserted into the damper  18  where the edge  62  engages with the upper lip  60  of the damper  18  such that the stem housing  22  is retained by damper  18 . This embodiment allows multiple pieces which can be better customized for many different applications and separately manufactured. This damper  18  also has a band  24  located between pairs of vertical lips  44  to bias the inner surface of side wall  34  against the outer surface of the spring S, thereby damping spring oscillations. 
     It will now be apparent to those skilled in the art that other embodiments, improvements, details and uses can be made consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent, which is limited only by the following claims, construed in accordance with the patent law, including the doctrine of equivalents.