Lynley has had chronic fatigue syndrome for many years and also has a back problem, so when she became pregnant she was not sure whether she would be able to lift her new baby. She approached TAD to assist with building some sort of hoist mechanism.
The task was assigned to volunteer Barry Lees, who says it was a challenging project and took a long time. There were a range of design considerations:
- the device needed to look nice, so it didn’t look out of place in the Qureshi’s house;
- it had to move easily around the house, through doorways and round tight corners;
- the mechanism had to lift the baby right from the ground;
- it had to keep the tray in its current place if the power failed in order to avoid injuring the baby;
- it had to be relatively quiet, so as not to upset or disturb the baby; and
- the components had to be as inaccessible as possible to small fingers as the baby grew older.
Barry initially looked at industrial lifters, but these were very heavy and looked too brutal for a domestic situation. They all relied on winches, and this would have been a much cheaper and easier option, but it posed an unacceptable risk because it wouldn’t hold the tray in place if the cable broke.
Barry therefore began from scratch, building a frame from 50mm square hollow steel which has handlebars for steering and is mounted on large castors. The tray for the baby has a 800x600mm wooden base and is open at the front end so Lynley can slide the baby onto it.
To protect the baby from falling, the tray has 300mm-high panels on the two sides and a higher wooden panel at the end that attaches to the frame. There are small slots in the side panels so that straps can be added if necessary, and the side edges are rounded off to create a surface that is not too sharp.
Barry made several versions of the lifting mechanism before he settled on a 3/4″ threaded rod which goes up inside the middle column of the frame. This is driven by two salvaged 12V electric motors with rubber V belts and pulleys, adjusted by Barry to be as quiet as possible, that are enclosed in a box at the bottom of the column.
The tray attaches to the rod with a large nut, and goes up and down as the threaded rod spins. Barry found that when there was weight in the tray it tipped slightly, jamming the nut on the thread and stalling the motor, so he added a ball bearing arrangement to hold the tray square when it was weighted. If the power fails, the rod stops turning and the tray stays in its current place.
The device is powered by a 12V gel-cell battery, housed with the motors in the box at the base of the column. There is also a built-in battery charger, so Lynley can charge the battery simply by plugging it into a power point.
Lynley also needed a simple mechanism to operate the lifter, which would not require much effort. Barry therefore set up a small, light switch on the handlebar which drives a relay to switch on the battery current.
The large panel at the back of the tray provides a partial barrier between the baby and the lifting mechanism. In addition, Barry made sure that the attachment to the vertical column was as narrow as possible, so it would be hard for a child to probe with their fingers.
Finally, Barry painted the device and ‘tried to make it look nice, not too agricultural’. He says this is often an issue because TAD volunteers are always trying to do things cheaply for clients, and this makes it harder to make one-off devices that are aesthetically pleasing.
Lynley’s son Haani is now 19 months old, and a big baby. She has been using the device in a number of ways, particularly for bathing him and in the bedroom. She is full of praise for Barry’s efforts, and the way he consulted her about what she needed. ‘He was wonderful,’ she said.