It may be that a passive articulation is all you’re after but there are times when you’ll want a door to close after you or a hatch to close by itself, saving you the bother. There are many ways of automatically closing doors or flaps but the most straightforward have to be spring hinges. They are intrinsically simple (think reliable) and do exactly as they are expected to.
Smaller spring hinges find use in flaps and hatches in cars or industrial machinery, the HG-SH is a fine example made from 304 stainless steel which gives good corrosion resistance for everyday use.
The “million cycle” hinge, which as it’s name suggests has been torture tested, has a collar separating the spring from the hinge for added smoothness and reliability. The average spring hinge may be tested to 200,000 cycles, which is usually more than enough but sometimes it’s reassuring to know that the hinge is unlikely to wear out in a normal service life.
The HG-BF3, also made from 304 stainless steel, can be got in a version that keeps doors closed and also a version that keeps doors open, used for example with spring-open lids when combined with a push latch.
Dampers to complete the solution
Sugatsune is keen to provide a complete solution to its customers so if a hushed close is required dampers could be the solution. UDH dampers have been silently dropping loo seats for a generation and can be used in their capsule form, engineered into your design or in hinge form such as the HG-JH14-50. When combined with a spring hinge automatic soft closing can be achieved.
A further enhancement would be a push-to-open catch like the PR4-PK or ESN-195, which will give you a hatch that opens automatically and quietly with a single touch.
Spring hinges for larger entry and interior doors share the same functionality but are more robustly made to deal with the greater loading and can be single or double action as desired.
Regularly used access doors will haemorrhage expensive heated air if left open and an open door can be an invitation to the unauthorised let alone an erosion of privacy. Door closers are cumbersome on a door with high traffic, what’s required is a simple mechanism like the SA or a double action hinge like the DA. A solid hinge using well understood engineering principles that will give a long and trouble free service life.
Doors with single action spring hinges feature in areas with health and safety hazards, take for example a door to a lift shaft or machine room. It may be that access is required but there is a need to guard against accidental entry, the SA keeps the door safely closed against entrance whilst exit is unimpeded.
An undamped spring hinge has a predictable and user friendly motion, a quality that makes them popular for busy areas. Both the SA and DA hinges have adjustable tension so they can be fine tuned to offer minimal resistance to opening keeping them easy to live with.
Access doors may well be exposed to the elements which is why the SA and DA hinges come in either aluminium or 304 stainless steel. However for corrosive marine or wash-down environments 316 stainless steel is the material of choice.