GB2172096A

GB2172096A - Airport lighting unit

Info

Publication number: GB2172096A
Application number: GB08605362A
Authority: GB
Inventors: David Harrison Conway
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-03-06
Filing date: 1986-03-05
Publication date: 1986-09-10
Also published as: WO1986005157A1; GB8505809D0; GB2172096B; EP0216814A1; GB8605362D0; AU5520086A

Abstract

An airport lighting unit comprises a lamp housing (1) adapted to be inset in the ground, having a lamp holder (3) and lamp (4) at its lower end and an elliptical reflecting surface (2). A support ring (5) is attached to the upper end of the lamp housing and supports a lens (9) located in an aperture (7). A cap (12) is fitted over the lens and is secured relative to the support ring by bolts (15) passing through a flange (1a) in the housing and threaded into the cap. Holes (8) are provided in the support ring (5) to secure the lighting unit in the ground. The cap (12) is provided with cut outs (12b) in order to allow the desired angle of light to be emitted from the lens.

Description

SPECIFICATION Airport lighting unit The present invention relates to a lighting unit for use at airports and more particularly to a lighting unit which is intended to be inset in the ground and have a lenticular portion at ground level for providing a desired illumination and indication to aircraft and airport vehicles.

Such airport lighting units are known and are in common use, but present constructions are complex and involve a large number of parts; therefore they are expensive. Furthermore structural failures are not uncommon.

It is an object of the present invention to provide an airport lighting unit of relatively simple construction, but which is robust and provides an efficient source of light.

According to the present invention a lighting unit particularly for airports, comprising a lamp housing adapted to be inset in the ground, a lamp holder at one end of said housing, which is its lower end in use, the interior of said housing defining a reflecting surface for light emitted by a lamp located in said lamp holder, a support ring attached to the other end of the said housing, which is its upper end in use, said support ring having a lens locating aperture disposed opposite said lamp holder, a lens unit located in said aperture and supported by said support ring and a cap disposed over said lens unit and secured relative to said support ring.

According to a preferred form of the invention the support ring is clamped in position between the lamp housing and the cap by means of bolts or studs extending from a peripheral region of the housing and threaded into the cap.

Preferably the lens unit comprises a lower region located in the lens receiving aperture of the support ring and an upper region shaped to produce the desired directional light emission from the lighting unit. The lens unit may be of any desired colour according to the colour of light to be emitted from the lighting unit. According to a preferred construction, the upper surface of the lens unit has a configuration providing a vee groove or recess extending along an axis normal to the axis of the lamp housing. The edges of the lens unit to either side of the longitudinal axis of the vee groove may be cut back or recessed to assist in producing the desired angle and direction of light emission.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross section through one embodiment of airport lighting unit according to the invention; Figure 2 is a plan view of the lens unit; Figure 3 is a cross section through the lens unit on the line Ill-Ill in Fig. 2; Figure 4 is a plan view of another embodiment of lens unit, and Figure 5 is a cross section through the lens unit on the line V--V in Fig. 4.

Referring to the drawings and particularly Fig. 1, the airport lighting unit shown comprises a lamp housing 1 formed as a steel or alloy casting defining an elliptical reflecting surface 2. A lamp holder 3 is mounted in an aperture in the base of the housing and carries a lamp 4. The external surface of the lamp housing 1 is formed with fins (not shown) to assist heat dissipation. Mounted on the upper end of the housing 1 is a support ring 5 having a central recess 6 which converges towards a lens locating aperture 7.

The support ring 5 has a peripheral flange provided with holes 8, for example six such holes, for receiving bolts for securing the lighting unit in position at an airport. The lens unit 9, which is shown in greater detail in Figs. 2 and 3, has a lower portion 9a shaped to fit in the locating aperture 7 and an upper surface including a central vee groove 10 and two concave recesses 11. The lens unit 9, which may either be moulded from glass or a plastics material is retained in position by a cap 12 having a peripheral flange 13 which engages in a recess 14 in the upper surface of the support ring 5.

The structure is secured together by threaded studs or bolts 1 5 having their heads 15a located in sockets in a peripheral flange la of the housing and extending through holes in the support ring to engage in blind threaded holes 16 in the cap 12. Two such studs may be provided diametrically spaced. Thus the support ring is held clamped between the housing 1 and the cap 12. The cap is made of metal and is provided with cut outs 12b, at least in the region of the concave lens portions 11 in order to allow the desired angle of light emitted through the portions 11 to be visible. The cap also includes a vee shaped reinforcing rib 1 2a projecting into but not touching the vee groove 10 in the lens.

The lens unit 9 is shown in greater detail in Figs. 2 and 3 and may be made of any desired colour according to the intended use of the lighting unit. As can be seen the lens unit is rectangular in plan and vee groove 10 extends normal to the axis of the lamp housing.

The two concave section recesses 11 are semicircular in plan and are located in the side edges to either side of the longitudinal axis of the vee groove 10. The angle of the vee groove and the radius of the concave section recesses are chosen to give the desired directional light emission from the lighting unit.

As will be apparent, the lighting unit is mounted at ground level with the lamp housing just below ground level and the support ring secured to the ground by bolts passing through the holes 8.

In the embodiment of lens unit shown in Figs. 4 and 5, the vee groove 20 is of wider angle than the vee groove 10 and the side edges 21 to either side of the longitudinal axis of the vee groove are cut back to a shallow vee form. These side edges are also provided with slightly inclined outer surfaces 22.

The lighting unit according to the present invention is of simple and robust construction and is of low profile so that it only projects a small distance, e.g. 15mm, above ground level.

The elliptical shape of the lamp housing directs light from the lamp source into the lens to a high light output, whilst the lens is a single component, which may be clear or coloured, and which focuses at required angles.

Parts of the lens may be silvered to form a reflecting surface. The lens cap is recessed into the main support plate giving great stability, and the cap, supporting ring and lamp housing are held together by bolts allowing quick dismantling etc. Moreover the lamp holder unscrews from the underside of the lamp housing enabling quick changing of the lamp.

The design of the lighting unit makes it particularly effective, after inserting the appropriate lens, and lamp, for use as a taxiway centre light, a stop bar light, a stand light, a runway centre line light, a runway side inset light, or a runway threshold inset light.

As an alternative, the lens may have a dichroic colour coating.

Claims

1. A lighting unit particularly for airports, comprising a lamp housing adapted to be inset in the ground, a lamp holder at one end of said housing, which is its lower end in use, the interior of said housing defining a reflecting surface for light emitted by a lamp located in said lamp holder, a support ring attached to the other end of said housing, which is its upper end in use, said support ring having a lens locating aperture disposed opposite said lamp holder, a lens unit located in said aperture and supported by said support ring and a cap disposed over said lens unit and secured relative to said support ring.

2. A lighting unit as claimed in claim 1, in which the support ring is clamped in position between the lamp housing and the cap by means of bolts or studs extending between a region of said housing and said cap.

3. A lighting unit as claimed in claim 1 or 2, in which the lens unit comprises a lower region located in the lens receiving aperture of the support ring and an upper region shaped to produce the desired directional light emission from the lighting unit.

4. A lighting unit as claimed in any preceding claim, in which the upper surface of the lens unit has a configuration providing a vee groove or recess extending along an axis normal to the axis of the lamp housing.

5. A lighting unit as claimed in claim 4, in which the edges of the lens unit to either side of the longitudinal axis of the vee groove are cut back or recessed.

6. A lighting unit as claimed in claim 5, in which the upper surface of the lens unit is generally rectangular in plan but with the longer sides of the rectangle disposed to either side of the vee groove being of vee shape.

7. A lighting unit as claimed in claim 4, 5 or 6, in which the cap is provided with a vee shaped reinforcing rib projecting into but not touching the vee groove in the lens.

8. A lighting unit as claimed in any preceding claim, in which the interior of the lamp housing defines an elliptical reflecting surface.

9. A lighting unit as claimed in any preceding claim, in which the external surface of the lamp housing is formed with heat dissipating fins.

10. A lighting unit as claimed in any preceding claim, in which the support ring has a peripheral flange provided with holes for receiving fastening means, such as bolts, for securing the lighting unit in position on the ground.

11. A lighting unit as claimed in any preceding claim, in which the cap is provided with cut outs dimensioned and positioned so as to allow the desired angle of light to be emitted from the lens.

12. A lighting unit particularly for airports substantially as hereinbefore described with reference to the accompanying drawings.