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You are an expert at summarizing long articles. Proceed to summarize the following text: 
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 12/834,833 filed on Jul. 12, 2010 and titled “HANDRAIL FOR STAIRCASE OR RAMP”. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to handrails for staircases or ramps, and more particularly to handrails that deter the use of the handrail as a slide. 
     DESCRIPTION OF THE RELATED ART 
     Many parks and public areas have staircases or ramps permitting easier navigation from one level to another in the park or public area. Typically, staircases  10  shown in  FIG. 1  have handrails  20  on their sides and some in the center as well. Handrails must conform to certain standards so that a person can hold on to them while navigating up or down the stairs. However, handrails have the unintended consequence of providing a convenient track for skateboarders. As shown in  FIG. 1 , skateboarders  30  jump their skateboard  40  onto these rails  20  and slide down, possibly damaging the rail or making it unfit for its intended purpose. It would be desirable to curb the actions of skateboarders. Thus, there is a need for a modification of the handrail that would permit people to use it for guiding and stabilizing themselves as they use the staircase or ramp, while at the same time deterring skateboarders from using the handrail. 
     BRIEF SUMMARY OF THE INVENTION 
     Embodiments described herein address the aforementioned need. Embodiments modify a conventional handrail in a way that preserves its function, while at the same time preventing or deterring its use by skateboarders. 
     One embodiment is an improved handrail for a staircase or ramp. The handrail includes an elongated cylinder and riser barriers. The elongated cylinder spans a length of the staircase or ramp is held at a height above the staircase or ramp by external supports. The riser barriers are solely supported by the elongated cylinder at a first set of spaced-apart locations along the elongated cylinder, no location in the second set coinciding with any location in the first set. Each of the riser barriers includes an extender portion and a riser portion, each riser portion being generally vertical and each extender portion being generally horizontal. Each of the extender portions has a length between a proximal end and a distal end, each of the proximal ends having attached thereto an arcuate portion that is adapted and fastened to the curvature of the bottom of the cylinder, and each of the distal ends being fastened to a respective riser portion at a position below the height of the elongated cylinder. The length of each of the extender portion holds a respective riser portion a horizontal distance away from the elongated member to permit passage of a hand along the elongated cylinder. Each of the riser portions has a length that extends above the height of the elongated member so as to deter sliding along the elongated cylinder. 
     Another embodiment is a plurality of riser barriers for a handrail of a staircase or ramp, where the handrail is an elongated cylinder supported at a height above the staircase or ramp by a plurality of external supports. Each of the riser barriers includes an extender portion and a riser portion. The plurality of riser barriers are solely supported by the elongated cylinder at a first set of spaced-apart locations along the elongated cylinder. The plurality of external supports support the elongated cylinder at a second set of spaced-apart locations along the elongated cylinder, no location in the second set coinciding with any location in the first set, each riser portion being generally vertical and each extender portion being generally horizontal. Each of the extender portions has a length between a proximal end and a distal end, each of the proximal ends having attached thereto an arcuate portion that is adapted and fastened to the curvature of the bottom of the cylinder, and each of the distal ends being fastened to a respective riser portion at a position below the height of the elongated cylinder. The length of each of the extender portion holds a respective riser portion a horizontal distance away from the elongated member to permit passage of a hand along the elongated cylinder. Each of the riser portions has a length that extends above the height of the elongated member so as to deter sliding along the elongated cylinder. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
         FIG. 1  depicts a skateboarder using the handrail as a slide; 
         FIG. 2  depicts a staircase employing an embodiment of the present invention; 
         FIG. 3A  depicts a transverse elevational view showing a first embodiment of the present invention; 
         FIG. 3B  depicts a bottom plan view of the embodiment shown in  FIG. 3A ; 
         FIG. 4A  depicts a transverse elevational view showing a second embodiment of the present invention; 
         FIG. 4B  depicts a left transverse elevational view of the embodiment shown in  FIG. 4A ; 
         FIG. 5A  depicts a transverse elevational view showing a third embodiment of the present invention; 
         FIG. 5B  depicts a right transverse elevational view of the embodiment shown in  FIG. 5A ; 
         FIG. 6A  depicts a transverse elevational showing a fourth embodiment of the present invention; and 
         FIG. 6B  depicts a right transverse elevational view of the embodiment shown in  FIG. 6A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments include a modified handrail  100  that prevents a skateboarder from using the handrail. An impediment or barrier is attached that preserves the functionality of the handrail while at the same time deterring its use by the skateboarder. 
     The embodiment in  FIGS. 3A and 3B  includes an elongated cylinder  110 , and a riser barrier  120  with extender portion  120   a  and a riser portion  120   b . The elongated cylinder  110  spans the distance of the staircase  10  and is held up by vertical supporting members  22  (see  FIG. 2 ) whose centers are spaced at approximately 48 inches. The extender portion  120   a  of the riser barrier  120  includes an arcuate portion  130  that is fastened to the elongated cylinder  110  using such fastening devices  150  such as bolts or rivets shown in  FIG. 3 . The riser portion  120   b  has a length that exceeds the thickness of the extender portion  120   a  plus the diameter “c” of the elongated cylinder by dimension “a”. In one embodiment, dimension “a” is about 3 inches and dimension “c” is about 1½ inches. The extender portion  120   a  has a length that assures the elongated cylinder  110  spaced away from the riser portion  120   b  by dimension “b”, which, in one embodiment, is about 1½ inches. Preferably, the riser barrier has ⅛ inch radius at all corners. The dimension “b” is sufficient to permit a user to slide his or her hand along the cylinder without interference, while the dimension “a” is sufficient to deter sliding on the cylinder. 
     The embodiment  200  in  FIG. 4A  and  FIG. 4B  includes an elongated cylinder  110  and an arcuate riser barrier  210  with a proximal end  220  and a distal end  224 . The proximal end  220  is adapted for affixation to the bottom of the elongated cylinder  110  by conforming its curvature approximately to the curvature at the bottom of the elongated cylinder. The proximal end  220  is affixed to the elongated cylinder  110  by means of tack welds  222  at points on either side of the cylinder  110  nearest to the proximal end  220  of the barrier  210 . The arcuate riser barrier  210  extends laterally and rises vertically so that the distal end  224  is spaced horizontally away from the elongated cylinder  110  by dimension “d”, and vertically away by dimension “e”. In one version, dimension “d” is approximately 1½ inches and dimension “e” is approximately 3 inches. As the arcuate riser barrier  210  rises from its proximal end  220  to its distal end, the riser barrier widens and then narrows. The arc-shaped arm has dimension “g” at its widest point and dimension “h” at its distal end. In one embodiment, dimension “g” is about 1½ inches and dimension “h” is about ¾ inches. Dimension “d” is sufficient to permit a user to slide his or her hand along the cylinder without interference while dimension “e” is sufficient to deter sliding on the cylinder. 
     The embodiment  300  in  FIGS. 5A and 5B  includes an elongated cylinder  110 , and a riser barrier having extender portion  320  and riser portion  310 . The extender portion  320  is curved downward between the proximal end  330  and the distal end  340  and holds the elongated cylinder  110  away horizontally from the riser portion  310  by dimension “k” and vertically away by dimension “p”, where, in one embodiment, dimension “k” is about 1½ inches and dimension “p” is about 1½ inches. The horizontal separation between the riser portion  310  and cylinder  110  permits the user to slide his/her hand along the cylinder  110  without interference, the downward curve of the extender portion  320  giving added room for the user&#39;s hand. The length of the riser portion  310  deters the skateboarder from sliding on the rail. As shown in the figures, the riser portion  310  has a thickness given by dimension “j”, which in one version is about ½ inch and a width given by dimension “n”, which in one version is about 1 inch. The proximal end  330  of the extender portion  320  is generally arc-shaped to conform and attach to the curvature of the elongated cylinder  110 . The distal end  340  of the extender portion  320  includes a generally flat, rectangular vertical portion. The flat, rectangular vertical portion fastens to the riser portion  310  and being wider than the riser portion  310  has a dimension of “m” by which it overlaps on either side the riser portion  310 . In one version, dimension “m” is about ⅜ inch. Any fastening device  350 , such as a bolt or rivet can be used to connect the flat portion of the distal end  340  to the riser portion  310 . The riser portion extends by dimension “q” below the flat portion  340  of the extender portion  320 . In one version, dimension “q” is about ½ inch. 
     The embodiment  400  in  FIGS. 6A and 6B  includes an elongated bar  112  and a riser barrier having extender portion  320  and riser portion  310 . The elongated bar  112  is generally rectangular or square in cross-section and may be hollow (shown) or solid. The extender portion  320  of the riser barrier is curved downward between the proximal end  332  and the distal end  340  and holds the elongated bar  112  away horizontally from the riser portion  310  by dimension “k” and vertically away by dimension “p”, where, in one embodiment, dimension “k” is about 1½ inches and dimension “p” is about 1½ inches. The horizontal separation between the riser portion  310  and bar  112  permits the user to slide his/her hand along the bar  112  without interference, the downward curve of the extender portion  320  giving added room for the user&#39;s hand. The length of the riser portion  310  deters the skateboarder from sliding on the rail. As shown in the figures, the riser portion  310  has a thickness given by dimension “j”, which in one version is about ½ inch and a width given by dimension “n”, which in one version is about 1 inch. The proximal end  332  of the extender portion  320  is generally flat to conform and attach to the bottom of the bar  112 . The distal end  340  of the extender portion  320  includes a generally flat, rectangular vertical portion. The flat, rectangular vertical portion fastens to the riser portion  310  and being wider than the riser portion  310  has a dimension of “m” by which it overlaps on either side the riser portion  310 . In one version, dimension “m” is about ⅜ inch. Any fastening device  350 , such as a bolt or rivet can be used to connect the flat portion of the distal end  340  to the riser portion  310 . The riser portion extends by dimension “q” below the flat portion  340  of the extender portion  320 . In one version, dimension “q” is about ½ inch. 
     In all of the above embodiments, the elongated cylinder or bar and riser barrier are fabricated with a material suited for environment in which the staircase or ramp is present. For example, if the staircase or ramp is outside in the elements, the elongated cylinder or bar and riser barrier may be fabricated in steel. Unless specified otherwise, the steel used has a suitable thickness to prevent bending or breakage. Suitable products that can be used for either the cylinder or bar are rectangular, square or round structural steel tubing such as HSS tubing. For round tubing, a length of 1.660×0.140 structural tubing is sufficient. For rectangular tubing, a length of 2×1.5×⅛ inch tubing is sufficient. Suitable products that can be used for the extender portion are brackets, such as the round saddle bracket 1970R, 1978R, 1990R, 1998R, or flat saddle bracket 1970F, 1978F, 1990F, 1998F, manufactured by The Wagner Companies. 
     Although embodiments have been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.

Summary:
An improved handrail for a staircase or ramp. In one embodiment, the handrail includes an elongated member such as a cylinder or bar that spans the length of the staircase or ramp and a riser barrier. The riser barrier has an extender portion and a riser portion. The extender portion of the riser barrier keeps the elongated member a sufficient distance horizontally from the riser portion that a person can slide his or her hand on the rail without interference. The riser portion projects vertically a sufficient distance above the elongated member to deter sliding down the elongated member. Thus, sliding on the member is deterred, while the function of the cylinder as a handrail is preserved.