A client came to us with a concept regarding a bracket for a hospital bed that was ‘lockable’ in which hand sanitiser could be stored securely. There were a range of specifications for this project that we needed to work with, and keep in mind during the design phase of this project.
The bracket had to secure the hand sanitiser bottle in order to reduce the risk of theft or patients drinking it, making it impossible for the lid to be unscrewed while in place. The client required the logo on the bottle to be visible at all times, and for the brail on the side of the bottle to remain accessible for visually impaired individuals.
In order to remain up to medical industry standards, the bracket had to be easy to clean, and any logo on the bracket could not be raised any more than 0.10mm to reduce growth of bacteria.
After the initial meeting to discuss these requirements, our injection mould design experts began creating 3 product ideas using 3D Computer Aided Design (CAD) models. Each model showed different aesthetic design changes, and a range of alternative locking mechanisms for the client to assess and choose from.
Following feedback regarding these designs, our design engineers manufactured a prototype of two chosen designs. Creating these prototypes helped us identify an issue with the locking mechanism. In order to keep the locking mechanism robust and safe from tampering, we used an existing profile for the key that unlocked the bracket, which was often used for other, similar products by our client, and added a positive lock (click) so that the lock sliding into place was audible.
Once these design changes were approved, we moved on to design the production tooling.
Time constraints and the budget meant that no further prototypes were made, however we manufactured the moulds in a way that made it possible to carry out further developments where they were necessary.
There were a range of challenges that we faced here. One of our main worries was that when tightening the locking mechanism, we may take it too far, and produce a part that would not operate at all.
The brail location on the side of the bottle also became an issue; a supporting structure, originally designed as part of the bracket, was in the way, and removal of this could lead to the bracket becoming flimsy and as such, compromising the security of the product as a whole. Lack of security would defeat the purpose of the product on a whole.
We had also manufactured this bracket in order to be unlocked by a specific key, but we were unsure if the product could be defeated by hand by a member of the public. The prototype had allowed us to determine that adult hands wouldn’t be able to remove the lid, but a child’s hands could potentially gain access, so we modified the profile here regardless.
The last challenge we faced was the logo. Typically these are raised for visibility, but with the constraints around this, it was uncertain whether it would be evident on the product.
We manufactured the two moulds so that we could address these concerns and challenges head on. They were a success, though we did carry out some slight remedial work to reduce excessive flash and stress marks. These are caused during the moulding process when the mould does not quite come together fully due to the nature of all the moving components. We were very happy with the results.
After the remedial work, we tested the product fully. The locking mechanism functioned well and gave a secure fit, and the lid could not be unscrewed from the bottle, while allowing the spout to travel through the front door without obstruction. The logo, raised at 0.10mm, is visible, though more visible is the label on the sanitiser bottle itself, and the raised logo does not pose any threats in regard to cleaning and bacterial growth. The support that we removed to regain access to the brail on the side of the bottle did not cause any weaknesses to the structure of the bracket, and allowed us to meet all of our client’s requirements both cost effectively and on time.
