Nothing About Us Without US Part Four Chapter 35 1 of 6 http www dinf ne jp doc english global david dwe001 dwe00146 htm part4chap35 Nothing About Us Without Us Developing Innovative Technologies For By and With Disabled Persons PART FOUR WHEELS TO FREEDOM 227 CHAPTER 35 A Gravity Powered Elevator for Wheelchair Accessibility Lack of Accessibility Getting to the upper floors of buildings with more than one level is in many countries a major obstacle for disabled persons especially wheelchair riders I the author am an advisor to PROJIMO in the village of Ajoya Mexico and live on the second floor of a small two story cement block building there My friends at PROJIMO rightly criticized me for living in inaccessible quarters But how could the upper level of my home be made more accessible to wheelchair riders The entry is via a steep wooden stairway little more than a solid step ladder that leans against a rectangular opening in the upstairs floor A ramp would be out of the question in the small room with so many steep stairs The only possibility would be some sort of elevator But a commercial motorized elevator or lift even a small one designed to glide up a stairway would be far too expensive Besides the supply of electricity to the village is too unreliable What to do A Simple Home Made Elevator To make the upstairs accessible to wheelchair riders a visiting inventor from Holland Reinder van Tijen together with two disabled craftspersons at PROJIMO Mart n P rez and Marcelo Acevedo helped to design and build a simple elevator lifted by gravity The elevator consists of a plywood platform mounted on a frame of steel tubing Welded to the frame are sets of ball bearings that roll along a diagonal pipe attached to the stairway 2 17 2007 9 32 PM Nothing About Us Without US Part Four Chapter 35 2 of 6 http www dinf ne jp doc english global david dwe001 dwe00146 htm part4chap35 The platform is lifted by a cable that passes through a hole in the cement block wall at the top of the stairs The cable rolls through pulleys which are made from the front wheels of old wheelchairs mounted on steel plates and bolted through the wall The cable is attached to a counter balance that rolls up and down the outer wall The counter balance is weighted with cement blocks the number of which can be varied so as to match the weight of the particular wheelchair rider When properly counter balanced the elevator glides effortlessly up and down the stairwell 228 Details of the elevator A short diagonal pipe welded to the metal frame of the elevator is equipped at either end with 4 sets of ball bearings These bearings fit snugly around the diagonal pipe next to the stairs Another set of ball bearings attached to the other side of the elevator frame rolls up and down the edge of the wood plank on the right side of the stairs 2 17 2007 9 32 PM Nothing About Us Without US Part Four Chapter 35 3 of 6 http www dinf ne jp doc english global david dwe001 dwe00146 htm part4chap35 Safety problems that needed solving The simple elevator worked well It has now been used by wheelchair riding visitors for more than 4 years Since the time it was built however visiting engineers warned that the elevator was unsafe The biggest risk factor they insisted was the lack of an automatic locking mechanism to safely hold the platform in place when it reached ground level As designed the platform had to be locked by the rider on reaching ground level A bolt was slipped through two holes one in the elevator frame and one in the diagonal pipe on which the elevator rolled As long as this bolt was in place before the rider rolled off the platform there was no problem But if he forgot and rolled off without inserting the bolt the elevator would rocket skyward This happened once when a small boy was standing on the edge of the elevator The platform took off like a rocket The surprised boy shot upward and fell off into a water tank below Fortunately he was unhurt But if anyone had been on the stairs when the elevator rocketed upward heaven help them 229 An automatic parking brake for the gravity run elevator Although visiting engineers insisted that the elevator needed an automatic locking mechanism none offered a design Finally it was Marcelo the disabled PROJIMO craftsperson who designed and built a fail safe automatic locking mechanism for the elevator He made it out of scraps of iron bar a spring and a few bolts Marcelo modified the design of a latch he built for PROJIMO s main gate which locks automatically when it swings closed He made it after the gate was left open at night and cows ate the banana plants 2 17 2007 9 32 PM Nothing About Us Without US Part Four Chapter 35 4 of 6 http www dinf ne jp doc english global david dwe001 dwe00146 htm part4chap35 The device is simple A U shaped iron bracket is bolted to the side beam of the stairs To this is attached a V shaped latch made by welding flat iron bars The latch which pivots on a bolt is pulled forward by a spring This latch hooks onto an upright post welded to the platform frame the post to which the elevator lift cable is attached When the elevator comes down the post pushes the latch out of the way Having passed the latch springs back hooking onto the post and locking the platform at ground level The device was tested 100 times and appears fool proof The only way to unlock the latch is to put enough weight on the platform so that it lowers a bit more then push the latch out of the way As an added safety mechanism the original bolt lock can still be used when the elevator is not in use giving double protection In conclusion Thanks to the warnings of visiting engineers plus the creative design and building skill of Marcelo the gravity run elevator is now much safer 230 Stairs Need Not Be So Big an Obstacle When There are Willing Friends 2 17 2007 9 32 PM Nothing About Us Without US Part Four Chapter 35 5 of 6 http www dinf ne jp doc english global david dwe001 dwe00146 htm part4chap35 Sometimes a barrier can become a chance for camaraderie Here friends of a boy in India help him up a long flight of steps A lot depends on our culture and point of view See the story by Mike Miles on page 172 Ramps In many circumstances ramps are far cheaper and more practical than elevators The recommended grade steepness of a ramp depends on the strength of its users and whether they have or need assistance Ramps for public use should have a very gentle slope so that persons with weak arms can go up