Technical Field
[0001] This disclosure relates generally to optical devices that deflect fields of view
and in particular to an optical assembly for deflecting the field of view in a work
vehicle to allow an operator to view areas that are obstructed.
Background
[0002] The field of view in a work vehicle may be obscured by the frames that bound the
windscreen and window apertures and by the structures of the vehicle body. The frames
of the apertures may constitute a termination or interruption in the available visibility.
The structure of the vehicle body, for example the engine compartment of a construction
vehicle, may also constitute a termination or interruption in the available visibility.
The drive of the vehicle may in most circumstances compensate for the obstruction
by altering position thereby varying the field of view through the apertures. There
nay be circumstances where the observer's ability to change his field of view is limited.
[0003] The present disclosure is directed, at least in part, to improving or overcoming
one or more aspects of the prior art system. The present invention seeks to provide
an assembly by which the field of view through an aperture that is obscured may be
deflected for a fixed viewing position.
Brief Summary of the Invention
[0004] In a first aspect, the present disclosure describes an optical assembly for improving
visibility in a work vehicle, the optical assembly comprising an aperture for viewing
operation of a worktool; and an optical device disposed at the aperture for diverting
light rays from a visually obstructed region to the field of view of the operator.
Brief Description of the Drawings
[0005] The foregoing and other features and advantages of the present disclosure will be
more fully understood from the following description of various embodiments, when
read together with the accompanying drawings, in which:
Fig. 1 is side view of a work vehicle having the optical assembly according to the
present invention.
Detailed Description
[0006] This disclosure generally relates to an optical assembly
10 for diverting light passing into a work vehicle
14. The optical assembly
10 may be suitably disposed in the vehicle for improving visibility for the operator
of the work vehicle. Optical assembly
10 may be disposed in the vehicle for improving visibility of work operations.
[0007] With reference to Fig. 1, the optical assembly
10 may improve visibility in a work vehicle
14 and may comprise an aperture
16 for viewing operation of a worktool
18 and an optical device
12 disposed at the aperture for diverting light rays
20 from a visually obstructed region to the field of view of the operator.
[0008] The aperture
16 may be located in a vehicle cabin
22. The aperture
16 may be defined by structural frames of the vehicle
14. The aperture
16 may be provided at the forward region of the vehicle. Light rays
20 from the front of the vehicle
14 may enter the vehicle cabin
22 through the aperture
16.
[0009] The optical assembly
10 may comprise a windscreen disposed at the aperture
16. The windscreen may be configured to fit in the aperture
16. The windscreen may include a central region through which light may pass substantially
without any deviation.
[0010] The optical device
12 may be coupled to the windscreen. The optical device
12 may be a separate element that may be disposed on the windscreen relative to a peripheral
region. In an embodiment, the optical device
12 may be chemically mounted to the windscreen. In an embodiment, the optical device
12 may be mechanically mounted to the windscreen. The optical device
12 may be supported in a supporting device at the windscreen.
[0011] In an embodiment, the optical device
12 may be incorporated into windscreen relative to a peripheral region. The optical
device
12 may form a part of the windscreen. The optical device
12 may be positioned within an opening formed in the windscreen.
[0012] In an embodiment, optical device
12 may be positioned such that light rays
20 pass through the windscreen prior to passing through the optical device
12. In an embodiment, optical device
12 may be positioned such that light rays
20 may pass through the optical device
12 to enter the cabin
22.
[0013] As regards the term "peripheral region", this is to be understood as the regions
adjacent the frames of the aperture. With the aperture defined by frames, the "peripheral
region" should be understood as referring to one side of the aperture adjacent a frame
and not to all sides of the aperture. For example in a four-sided aperture, the "peripheral
region" may be a region along one side thereof and not the remaining three sides of
the aperture.
[0014] The optical device
12 may be disposed adjacent the upper peripheral region of the aperture. The optical
device
12 may be disposed so as to divert the light from an obstructed region to the field
of sight of the operator. The optical device
12 may be aligned with the seating position of the operator.
[0015] In an embodiment, a portion of the optical device
12 may be provided. The portion of the optical device
12 may be suitably dimensioned for the operator to visualize worktool
18.
[0016] The optical device
12 may be located at the upper region of the windscreen. In an embodiment, the optical
device
12 may be located at the upper region of the front windscreen. In an embodiment, the
optical device
12 may be located at the upper region of the rear windscreen.
[0017] Light rays
20 arriving from a visually obstructed region may be diverted through an angle by optical
device
12 so that the direction of the diverted light
21 may be closer to the central region of the aperture
16. The optical device
12 may cause the light rays
20 to bend at the peripheral region. The light rays
20 may bend to become diverted light rays
21 as they pass through the optical device
12 from the visually obstructed region towards the operator.
[0018] In an embodiment, the angle through which the light rays
21 are diverted may be greater closer to the edge of the peripheral region adjacent
to the frame of the aperture. In an embodiment, the angles through which the light
rays
21 are diverted may preferably decreases away from the edge of the peripheral region
adjacent to the frame of the aperture.
[0019] The diversion of the light rays
21 may be achieved through refraction. In an embodiment, the angle through which the
light rays
21 are diverted may be greater closer to the edge of the optical device
12. In an embodiment, the angles through which the light rays
21 are diverted may preferably decreases away from the edge of the optical device
12 towards the centre.
[0020] The optical device
12 may vary the diversion of the light rays
21 over the width thereof. Optical device
12 may preferably introduce no step-change in the diversion of the light diversion rays
12 at its edge adjacent to the frame of the aperture
16.
[0021] The optical device
12 may have not have an inclination of the surfaces (that is the surfaces are substantially
parallel) at a point inward from the frame of the aperture
16. The inclination of the surfaces of the optical device
12 may increase progressively towards the frame.
[0022] The optical device
12 may be a negative lens. The optical device
12 may be a cylindrical negative lens.
[0023] In an embodiment, the optical device
12 may be mounted to the vehicle frame in the vehicle cabin
22. A supporting body may be mounted to the vehicle frame to hold the optical device
12 in position.
[0024] The optical device
12 may be a Fresnel lens. A side of the Fresnel lens may be a plane, smooth flat front
face and a serrated rear face comprising a plurality of prism-like facets. The facets
may be separated. The Fresnel lens may have a pattern defined by the serrated rear
surface.
[0025] At least a portion of a Fresnel lens may be disposed at the aperture
16. The portion of the Fresnel lens that diverts the light rays
20 downwards may be positioned at the top of the windscreen. The portion of the Fresnel
lens may be positioned at the top centre of the windscreen.
[0026] A whole Fresnel lens may be positioned on the windscreen. The operator may use a
selected portion of the Fresnel lens to obtain the desired view of the worktool
18.
[0027] The Fresnel lens may be disposed in a fixed relative positional relationship with
respect to a peripheral region of the aperture
16. The Fresnel lens may be disposed in other areas, for example at window apertures.
[0028] The skilled person would appreciate that foregoing embodiments may be modified or
combined to obtain the optical assembly
10 of the present disclosure.
Industrial Applicability
[0029] This disclosure describes an optical assembly
10 for improving visibility for an operator of a work vehicle. In particular, the optical
assembly
10 may improve visibility of the fork tips and/ or stabiliser feet from the cabin of
Backhoe Loader.
[0030] The optical assembly
10 may be used where components and structures of the vehicle frames, that are positioned
or dimensioned according to work requirements, may obstruct visibility of the operator.
Obstruction to the field of view may occur particularly at the forward region of the
vehicle. As an example, the forward region of the work vehicle may have the engine
compartment. The forward viewing region may be restricted between the upper frame
of the windscreen aperture and the upper portion of the engine compartment.
[0031] The operator of the work vehicle may partially overcome the obstruction by repositioning
his field of view. However, any repositioning may require time and may not fully compensate
for the obstruction.
[0032] Improvement in visibility may be achieved by disposing the optical device
12 in the vehicle cabin. The optical assembly
10 may divert light passing through an aperture provided in the vehicle cabin. The optical
assembly
10 may divert light at a peripheral region of the aperture.
[0033] The optical assembly
10 may include the application of the optical device
12 to the vehicle windscreen at a region where light from an obstructed region may be
diverted to the field of view of the operator. Through the optical assembly
10 it may be possible for the operatore to effectively to have a field of view in which
the obscuration effect vehicle components or structures may be compensated and, in
some cases, eliminated.
[0034] Accordingly, this disclosure includes all modifications and equivalents of the subject
matter recited in the claims appended hereto as permitted by applicable law. Moreover,
any combination of the above-described elements in all possible variations thereof
is encompassed by the disclosure unless otherwise indicated herein.
[0035] Where technical features mentioned in any claim are followed by references signs,
the reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly, neither the reference signs nor their absence have
any limiting effect on the technical features as described above or on the scope of
any claim elements.
[0036] One skilled in the art will realise the disclosure may be embodied in other specific
forms without departing from the disclosure or essential characteristics thereof.
The foregoing embodiments are therefore to be considered in all respects illustrative
rather than limiting of the disclosure described herein. Scope of the invention is
thus indicated by the appended claims, rather than the foregoing description, and
all changes that come within the meaning and range of equivalence of the claims are
therefore intended to be embraced therein.