With traditional (knuckle) hinges, weight and stress is concentrated solely at the hinge locations. The "downward" weight of the door over loads the bottom hinge resulting in knuckle and pin failure. The lateral "top heavy pull away" stress tears out the top hinge splitting both door and frame allowing the door to drop out of alignment, resulting in binding at frame and threshold with resultant damage to floor surfaces. Lock/latch misalignment affects security and safety. Greatly increased stress on the door closer leads to premature failure. All components - door, frame and hardware - are all subject to on going expensive repair and maintenance.

With Sealmaster Continuous Geared Hinges, weight and stress is dissipated down the entire hinge and evenly 'absorbed' throughout the entire door and frame length. There are no pins to wear or lift. Hinge gearing and multi Delrin bearings maintain 'true' alignment providing effortless opening and maintenance free operation for door weights to 245Kg - over FOUR TIMES the weight of an average one hour door. Sealmaster Continuous Geared Hinges are a maintenance free and cost effective solution.

A recent survey into building maintenance costs revealed an unacceptable level of expenditure to maintaining and repairing fire resisting doorsets and associated hardware, which are subjected to excessive impact and stress. Whilst a drain on financial resources, the problems were compounded by rejection by the Fire Officer of the fire door's efficiency and ability to hold back fire and smoke. Failure of these doors directly compromised the building’s safety as they were installed to maintain the integrity of means of escape routes.

Incorrect Specification remains the prime cause of hinge and doorset failure associated with excessive impact and stress. Repairs involve hinge and split frame or lipping replacement plus realignment of the door and the closing mechanisms. Often the same doorsets may be repaired 3 or 4 times per year at considerable expense.

The survey embraced hospitals, universities, schools, care homes and high occupancy commercial buildings.

Conventional butt hinges do not solve the problem of absorbing high impact levels and stress.

Sealmaster have developed and tested a continuous geared hinge which incorporates a unique method of intumescent fire seal protection. Unlike conventional continuous hinges, the Sealmaster hinge is a pinless assembly, there are therefore no pins to wear out.

A Sealmaster hinge consists of two full height, paired and geared leaves. Each leaf rotates evenly from top to bottom, riding on multi Delrin bearings which provide an extremely low co-efficient of friction.

The geared leaves and bearings are embraced by a full length protective channel cap and include specially formulated intumescent strips which protect the entire length of the hinge and are discreetly fitted.

Sealmaster Continuous Geared Hinges are designed to ensure:

• Ease of opening, even on heavy weight doors.
  

• Elimination of warping on hinge side of door or door drop.
  

• Maintenance of lock / latch alignment and subsequent security.
  

• Distribution of weight and impact down the entire door and frame length.
  

• Integrity of the door in a fire is maintained.
  

Sealmaster continuous geared hinges take no longer to fit than conventional hinges and when used for upgrading existing doors, they usually cover existing mortice points.

Sealmaster continuous hinges, incorporating unique intumescent seals, meet the Technical Fire Resistance requirements of Approved Document B to the Building Regulations 1991, Appendix B.B5 and have been tested to BS476 Part 22 for 30 and 60 minutes.

• Designed to absorb impact and stress along the full length of the door and frame for the life time of the structural opening.
  

• Ensures alignment of door with no drop or binding after 1.5 million cycles on 75 kg doors, dramatically exceeding requirements of BS 7352: 1990.
  

• Gearing avoids the need for force to open heavy doors, of construction up to 245 kg.
  

• Eliminates repetitive maintenance of hinges, lipping and frame arising from hinge failure.
  

• Tested and approved for use on FD30S and FD60S doors to BS 476 Parts 20 & 22.
  

• Eliminates need to repeatedly replace conventional hinges, frames, lippings during the life span of the opening.
  

• Intumescent protected Sealmaster continuous geared hinges are cost effective solutions for maintaining stress free doors.
  

• Meets the Fire Resistance requirements of Approved Document B to the Building Regulations 1991, Appendix B:B5.
  

• Eliminates dropping of door, thus maintaining lock or latch alignment and security.
  

• The Sealmaster hinge is maintenance free and requires no lubrication.
  

The Sealmaster Continuous Geared Hinge is available in three versions for use on upgrading existing doorsets as well as new doorsets.

Each hinge is available in standard or heavy duty version according to the weight of door, extent of expected impact and stress. Standard hinges contain 14 bearings distributed down the height of the door which absorb weight, impact and stress and are suitable for doors up to 125 kg in weight. Heavy duty hinges contain 27 bearings and are suitable for doors up to 245 kg in weight.

All hinges are produced from extruded aluminium alloy to extrusion grade 6063 - T6 comprising three interlocking sections in a pinless assembly.

Standard finish is natural anodised with dark bronze or gold anodised finishes available to order.

All hinges are supplied in 2.1 metre lengths but can be cut to suit door height (see fitting instructions). Longer length hinges for commercial doors up to 3 metres in height and 350 kg weight are also available on request.

Where the Sealmaster hinge does not conceal the mortice exposed after the old hinge is removed such areas are reinstated with Sealmaster intumescent pads which are simply surface fixed and over-finished as necessary.

Sealmaster hinges are not limited in application to fire resisting doorsets. They are eminently suitable for any door which is subject to high levels of impact or stress, whether they be timber, aluminium or steel.

Additional features of the full length protective channel cap provides the ability to ensure privacy in areas such as lavatories, executive offices and examination rooms.

Smoke leakage is equally successfully contained due to the features of the geared hinge cap; independent tests at Warrington Fire Research Centre to BS476: 31.1 confirm this. Full details are available on request.

Heavy reinforced doors as used in X-ray rooms, typically 100 kg, can be easily operated without force, reducing wear resistance to closing devices.

In addition to extensive fire testing at Sealmaster's Fire Testing facility at Pampisford, successful independent fire testing has been undertaken at Warrington Fire Test Centre on single acting pairs of double doors, the most onerous form of test devised. Results: FD30S - 39 minutes, FD60S - 82 minutes. Details are available on request.

Sealmaster Continuous Geared Hinges meet the Technical Fire Resistance requirements of Approved Document B to the Building Regulations 1991, Appendix B.B5.