Truncated dome insert pins with flexible Mylar Layout Grid

Abstract

A plastic device, in the shape of a truncated dome, affixed to a pedestrian sidewalk, crosswalk or platform by use of a flexible Mylar layout grid and a drilled and glued insert location , placed to provide a tactile and visual alert to disabled persons as to the location and edge of a platform or walkway, where the sidewalk or walkway transitions to a roadway or elevation change. The device consist of a molded plastic “truncated dome”, with an integrally molded stem and a pre drilled Mylar mat positioning guide to ensure the truncated domes are installed with in the guidelines of the American's with Disabilities Act. The truncated domes will provide the correct tactile alignment, slip resistant surface, as well as the correct contrast in color between the truncated domes and substrate as required in the American's with Disabilities Act.

1 .) The flexible mylar layout grid allows for the correct placement of the truncated dome insert pins on an existing substrate allowing for the inevitable flexion and tension of the concrete surface finish. The Mylar layout grid is pre-marked and drilled and is transparent. The layout grid can either be butted together or overlaid, for longer applications, such as a subway platform or longer sidewalk to pavement transition, and still maintain the correct center to center spacing of the insert pins as referenced by The Americans With Disabilities Act. A Carpenter will be able to use the layout grid without extensive additional training or laborer personnel could be trained to do the installation in a short period of time. Layout and installation can be accomplished with tools and personnel already in a contractors standard inventory. This layout and installation system does not interfere with normal business activities and does not require the closing of sidewalks and entrances for a long period of time. Sections as small as four feet can be closed and installed in as little as 2 man hours.  
   
   
       2 .) The polycarbonate insert pins are injection molded and have an integral anti-slip surface molded into the 18 mm top surface. The plastic is stabilized against normal ultraviolet solar radiation and are molded in a high visibility color, such as red, orange or blue. The size and shape, as well as the contrast between the insert pins and underlying substrate, conform to the requirements as stated in the Americans with Disabilities Act.  
   
   
       3 .) The insert pins are all of the same shape and size and are interchangeable with each other. The standard size allows for replacement of an individual pin should one become broken or missing due to maintenance or snow removal operations. This is far preferable than having to remove a complete pre-molded clay tile to replace one broken truncated dome surface. No concrete needs to be removed for the placement of the plastic truncated dome insert pins. Should one become missing, the contractor needs only to re-drill the existing location point, by drilling out the remaining stem piece, and then glue in a new truncated dome insert pin.  
   
   
       4 .) Installation may be accomplished using tools already in the contractor's inventory and with minimal additional training of existing skilled or semi-skilled personnel. No rental or specialty tools or equipment are required for normal installation. No special tool platforms or machine jigs are required. Installation in new concrete can be performed by using the layout grid during the finishing process and inserting the pins into the pre-marked hole locations in the fresh concrete.  
   
   
       5 .) The high visibility color and high contrast with the underlying substrate, allow the limited sighted individual to easily distinguish between sidewalk and pavement areas. The 20 mm spacing between dome structures allows for wheelchair wheels to easily negotiate the tactile warning strip without having to roll over the dome structures. The integrally molded anti-slip surface provides a traction area when rain or snow is present.