A BETTER VIEW
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AHEAD
Our Bodybuilding Expert Deals with the Windscreen and Front Windows of the Coach and Bus, introducing the Subject of Ventilating the Driver's Cab
AN efficient windscreen is a safety device, because protection from the weather helps the driver to concentrate his attention on the road, but such protection must be afforded with a minimum of obstruction to the driver's outlook. The use of metal for the
frame allows it to be reduced to the smallest proportions. This is a great advantage when the large windscreen of a full-width driving compartment has to be divided into near-side and off-side panels, in order that support may be provided in the centre and so as to reduce the size of the upper adjustable panel or panels.
Care should be taken to ensure that the 4orizontal division line between the fixed and opening panels Is not in the direct line of sight.
The bottom line of the windscreen may be straight or curved. From • p50 the driver's point of view the latter type is to be preferred, especially when the line is close to the top arch of the bonnet and curves well down at tie sides.
The frame of the screen consists of metal channelling in which the glass is bedded in rubber. The side channels of an opening panel are lipped so that a watertight joint is formed when the panel is closed. A similar joint is made on the bottom edge, or the glass overlaps the top edge of the fixed panel below it: The top channel is hinged to the wood rail of the body above the windscreen, or this channel includes a tube with a rod passing through it, forming a base upon which the panel may. swing.
Many screens have sun visors of /Petal or tinted glass. 'These should always be fitted in cases where there is little or no projecting roof canopy.
The Objection to Windscreens.
The objection originally made to the provision of glass windscreens on service buses was not on account of obstruction formed by the necessary framework, but rather because of the loss of efficiency which might occur owing to the clouding of the glass in wet weather. '
Under the Conditions of Fitness Regulations the fully enclosed driver's cab must have an automatic windscreen wiper, and, although the screen must have a hinged panel, the cab must be adequately ventilated without the need for opening the screen.
The Construction and Use Regula tions provide that qn and after Januarx 1st, 1937, windscreens a n d front windows shall be of safety., glass, but with new vehicles this stipulation is being anticipated to a comparatively large extent.
When the screen is mounted between sloping wood pillars, the latter may be continued to the floor level -and, 'with the pillar at the doorway, f orm the chief items of a strongly braced Structure. The
sloping . pillar tops and the bottom rail of the windscreen opening are rebated for the reception of the screen, whilst the top rail has a quadrantshaped recess for the -accom-. modation of the tube on which the adjustable panel of the screen swings.
The canopy above the screen is formed by lapping a shaped baton to the projecting ends of the cantrails. The space between the canopy rail and windscreen is boarded on the underside, and longitudinal ribs are framed between the canopy rail and the first hoopstiek to carry the panelling of the peak of the roof.
Eliminating Wood Pillars.
A sloping screen assembly 'often includes metal-framed side windows which occupy the space between the sides of the windscreen and the front entrance. .A similar arrangement is provided for the half-width cab, with the advantage in each case that no wood pillars are necessary.
The closer the screen is to the driver the better he can see through it and adjust it. The rearward position of the windscreen is limited by the steering wheel, but the clearance between steering wheel and . glass should not be reduced to a minimum, because this may unduly curtail the size of the cab and thus increase the difficulty of keeping it well ventilated.
A sloping screen deflects the air. currents upwards and, if there be a set of louvres above it, fresh air is constantly passing through them, whether the screen be open or closed. The deflecting action of the staggered windscreen may also be utilized to extract air from the cab. To accomplish this the screen should consist of a lower vertical panel and two upper sloping ones arranged one behind the other. The space at the top between the sloping panels is left open.
The oncoming air currents pass over the outer sloping panels, or through a gap which improves the driver's vision, and are deflected by means of the inner sloping panel. An ejector action is thus set up, with the advantage that the gap may be kept open in all weathers and no
wiper is required. This arrangement has been patented and is called the Syt-Gap windscreen.
When the front near-side window of the main saloon is unobstructed by the cab, as with a forward control vehicle, it is usually a fixed one. It is suggested, however, that it should be made up in the same way as a wind in this type of for. ward -control co ach there is a sloping screen for the driver's cab and the near side of the passenger-seating saloon. As the off-side portion of the bulkhead is upright the use of a triangular windowisnecessitated
at the point A. screen, especially when this window is staggered, as is sometimes the case with coaches.
If this window be sloped, the offside half of the bulkhead is usually vertical and there is a triangular space to fill at the end of the near side Of the cab. This may be panelled or glazed.
Upper-saloon Windows.
The front windows of the upper saloon of a double-decker also constitute a windscreen and, although the view ahead may not be so important as with the drivees cab, nevertheless, any improvement in the natural lighting of the upper saloon adds to its attractiveness.
The better the natural lighting, the later the vehicle can be used without illuminating the interior, thus saving • the batteries..
The passengers occupying the front seats have the best view, and the others must rely on the side windows for their enjoyment of the passing scene. It is suggested that more passengers would obtain a better view forwards if the front of -the saloon were divided into three windows, the centre one being the -largest, not only in width, but also in depth, it extending below the waist line, where it would be protected
by inside guard rails. Such an arrangement would introduce a novel• outline for the front-belt panel.