What's the Matter?
An innovative approach for independence and adaptability
Rollators are wheeled devices which help the elderly and physically impaired in retaining their mobility and independence. However, getting around in different use cases is still inconvenient with existing products. We are using a push-down rollator as a base for our design, which uses springs that actuate as you naturally apply force downwards on the rollator, rather than a pneumatic brake that has levers which can be difficult to squeeze for some people. However, this type of rollator still has issues that limit its adaptability for each user and situation, which our three mechanisms aim to address.
01
Adjustable Braking Force
Current models for push-down rollators fail to account for situations in which rollators are loaded with weight such as groceries or laundry. Our design allows users to control the amount of braking force required to engage the brake, meaning it can be used even while weighted down. The design also accommodates for a greater range of users that may want to support more or less of their body weight during normal usage.
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The design functions by compressing a spring different amounts to control the braking force. To engage the brake, the wheel must push up against the spring, moving roughly half an inch upwards. The force required to move increases as the spring is pre-tensioned. A rope pulls a delrin disk against the spring, increasing the required braking force.
The amount of tension is controlled by a handle found in the center of the rollator. By turning the handle, the user winds pulleys on either side of the rollator until the desired spring tensioning is reached. The two pulleys are connected via a live hex axle so that the tension on both sides of the rollator can be controlled simultaneously. The tension is then held in place via a ratchet that can be released to decrease the spring tension.
02
Modular Handles
Most users utilize arched rollators, but prolonged use of arched rollators can cause the user to become tired and lean forward too much. Upright rollators allow the user to stand up straight, providing the user with reduced stress and better posture. Our design allows the user to switch between the arched and upright positions. This way if the user becomes tired, they can switch to the upright position where they can maintain a better posture. Users can easily switch from one position to the other by clicking a button on the arm and rotating it until it locks in position.
03
Resistive Wheels
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Gravity causes the rollator to roll faster than the desired speed of the user, potentially pulling them forward and causing them to lose their balance. Our design provides resistance only at high speeds by using an eddy current brake. Two magnets are positioned close to aluminum disks on the rollator wheels to create an eddy current force that resists the motion of wheel rotation. This force increases exponentially with the speed of the rollator. Thus, it is able to provide resistance at high speeds when it is needed without impacting the motion of the rollator at slow speeds. This design also does not involve any physical contact as eddy current brakes dissipate energy through heat.