Bicycle shield device

The invention provides a bicycle shield device adapted to be removably connected to a bicycle attached to a carrier for transportation by a highway vehicle so that the shield device is interposed in the airstream immediately ahead of the bicycle, in order to shield the bicycle from impact by foreign objects during such transportation. The device of the invention generally comprises an elongate narrow body to shield the bicycle frame and frame-mounted components, and a pair of opposed arms extending outwardly from the body in generally perpendicular relation to shield the bicycle handlebars and handlebar-mounted components. Various embodiments and adaptations for accommodation of different bicycle-to-carrier attachment systems are also disclosed.

FIELD OF THE INVENTION 
The present invention generally relates to shield devices, and, in its 
preferred embodiments, more specifically relates to shield devices 
intended for use during the transportation of bicycles on a 
vehicle-mounted carrier rack for the purpose of shielding the bicycle 
against impact of stones, insects, and other objects. 
BACKGROUND OF THE INVENTION 
As the sport of bicycling has become more popular, transportation of 
bicycles for considerable distances on vehicle-mounted racks has become 
increasingly common, and the incidence of damage caused by impact of 
stones, insects and other objects against bicycles during such 
transportation at road speeds has become more widespread. The cost of 
bicycle frames and components has increased significantly in recent times, 
and the concern with prevention of damage to such frames and components 
has increased correspondingly. Prior art approaches to solution of those 
problems have been limited and have not been fully satisfactory. 
One such approach involves fully enclosing the bicycle in a bag of canvas 
or similar material before mounting the bicycle on the carrier rack. While 
such enclosures are somewhat effective in deflecting objects from direct 
impact against the bicycle, or at least minimizing the damage from impact, 
they are cumbersome and time consuming to use, difficult to clean, and 
display a pronounced tendency to flap in the wind generated by vehicle 
motion, substantially increasing wind noise. In addition, the flapping of 
the material may damage or disturb the adjustment of delicate components 
of the bicycle. 
Another approach has utilized a low profile deflector structure 
interconnected to the front of the bicycle carrier rack so that the 
deflector structure extends horizontally across the entire width of the 
carrier, but extends vertically through only a very small portion of the 
height of the bicycles to be mounted and transported thereon. This 
approach is very similar in concept to the known bug deflector devices 
intended to be mounted on the hood of an automobile in order to at least 
partially deflect bugs from the windshield of the automobile, as 
illustrated, by way of example, by U.S. Pat. No. 4,547,013 to McDaniel. 
While such structures are reasonably effective in deflecting bugs from 
vehicle windshields, they have not been similarly effective when used with 
bicycles. 
A somewhat similar deflector device designed to be mounted on the roof of a 
vehicle is also known in the prior art, as illustrated by U.S. Pat. No. 
4,206,942 to Nudo, et.al. Such devices generally comprise a rectangular 
shield mounted on the roof of a vehicle with the long axis of the 
rectangle across the roof and the short axis extending upward from the 
roof at an incline toward the rear of the vehicle. As viewed in the 
direction of air flow against the structures, such roof mounted deflectors 
are essentially larger versions of the hood mounted bug deflectors, and 
suffer essentially the same disadvantages in terms of effective shielding 
of a bicycle to be transported on the roof of the vehicle, as well as some 
additional disadvantages. The prior art deflectors do not normally extend 
to a sufficient height to fully shield the bicycle frame structure, and if 
extended to a sufficient height would create a severe aerodynamic drag 
highly detrimental to vehicle fuel efficiency. Because of the high wind 
load such deflectors typically require substantial support structures 
which leave insufficient space on the roof of most passenger vehicles to 
mount a bicycle and make the deflector structure heavy and cumbersome. 
The prior art further includes a number of devices generally described as 
farings, designed to be mounted on a bicycle frame for protection of the 
rider and/or luggage while the bicycle is being ridden at normal pedaling 
speeds. Examples of such devices may be found in U.S. Pat. No. 4,655,497 
to Mallett, U.S. Pat. No. 4,790,555 to Nobile, and U.S. Pat. No. 4,813,583 
to Carpenter. While some faring-type devices provide some protection to 
the bicycle frame and components, any protection is a purely tangential 
result of their primary purpose and is incomplete at best. The structures 
of the faring-type devices are not designed to withstand wind loads 
imposed at vehicle highway speeds in any event. 
Therefore, there remains an unfulfilled need for a shield device which 
effectively and efficiently protects a bicycle mounted on a carrier rack 
against impact by foreign objects during transportation at passenger 
vehicle highway speeds. 
SUMMARY OF THE INVENTION 
The present invention provides a structurally simple, inexpensively 
produced, and highly effective device to shield a bicycle mounted on, 
especially, a vehicle roof carrier rack, against impacts from foreign 
objects during transportation of the bicycle at carrier vehicle highway 
speeds. The device of the invention generally comprises an elongate body 
adapted to be removably attached to the bicycle itself or, alternatively, 
to the carrier rack immediately in front of the bicycle as mounted on the 
rack, such that the device is in the airstream generated by movement of 
the transport vehicle. 
The length of the body of the device is adapted such that, with the device 
in place, the upper end of the body of the device extends to a point 
horizontally aligned with or slightly above the highest point of the 
bicycle mounted on the carrier rack. The longitudinal axis of the body may 
be straight, or may be curved through its length to match the curvature of 
the leading wheel of the bicycle for use with carrier designs in which the 
bicycle is mounted with the front wheel in place or with the rear wheel 
toward the front of the transport vehicle. The width of the body is 
substantially less than the height, being slightly wider than the lateral 
extension of the bicycle frame and components, other than handlebars, from 
the longitudinal axis of the frame. The body is curved in cross-sectional 
configuration in a generally semi-circular arc with the arc centered on 
the line of air flow against the bicycle during travel of the vehicle. The 
edges of the body, at the ends of the arc, are preferably slightly flared 
to outwardly deflect air and create an "envelope" of relatively still air 
around the bicycle at transport vehicle road speed. 
In the case of most multi-geared racing or touring bicycle models, a 
deraileur component is mounted on the axis of the rear wheel and extends 
outwardly from the longitudinal axis of the frame a greater distance than 
other components, except handlebars and pedals, and the pedals are 
typically at approximately the same height from the ground as the 
deraileur. In the preferred embodiments of the device, the body is 
slightly wider through the portion of the body interposed in the air 
stream in front of the deraileur and pedals, to shield those wider 
components of the bicycle. 
The preferred embodiments of the device further include a pair of arms 
disposed in opposed positions on either side of the body and extending 
outwardly therefrom. The arms are typically each formed in an elongate 
L-shaped longitudinal configuration, generally matching the typical front 
profile of the handlebars of the bicycle, and are disposed on the body at 
a height so as to intercede in the air stream immediately in front of the 
handlebars with the bicycle on the carrier rack and the device in place. 
The cross-sectional configuration of the arms of the device is curved in 
similar manner as the curvature of the body, and the edges of the arms are 
preferably slightly flared for wind deflection. 
With a bicycle attached to a vehicle-mounted carrier rack and the device of 
the invention in place on the bicycle or, alternatively, on the rack, the 
body of the device is interposed in the windstream to directly shield the 
bicycle wheels, frame, and frame mounted components, and the arms of the 
device are similarly interposed to directly shield the handlebars and 
handlebar-mounted components such as brake levers. Therefore, objects such 
as stones and insects thrown from the road surface or intersected by the 
line of travel of the vehicle and bicycle will impact the shielding device 
of the invention instead of the bicycle, thus shielding the bicycle from 
such direct impacts. In addition, the flared edges of the body and arms of 
the device function as airfoils to deflect oncoming air into a curved path 
extending sufficiently to the rear of the device to encompass the length 
of the bicycle. As a result of that deflection, an envelope of relatively 
still air is formed around the bicycle, with a boundary of fast moving air 
which serves as a barrier to the passage of, especially, relatively light 
objects such as insects and even raindrops. Therefore, the device of the 
invention creates a primary barrier against impact by objects directly in 
the line of vehicle travel, as well as creating, through its airfoil 
effect, a secondary barrier effective against objects which would impact 
the bicycle on a line offset from the line of vehicle travel. 
The device of the invention is preferably formed as a one piece 
construction from a lightweight plastic material of sufficient strength 
and fracture resistance to withstand impact of foreign objects at vehicle 
road speeds, but the device may be formed of other materials, such as 
metal, with suitable characteristics. In addition to shielding the bicycle 
against object impact, the device of the invention is aerodynamically 
efficient and eliminates much of the air turbulance created by an 
unshielded bicycle frame and components, thus reducing wind noise and 
increasing fuel economy. These and other structural and functional 
features of the preferred embodiments of the device of the invention will 
be described in more detail with reference to the accompanying drawing 
figures.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
With reference now to the drawing figures, especially FIGS. 1 and 2, the 
bicycle shield device of the invention, generally designated by reference 
numeral 10, will be seen to comprise the two major components of body 12 
and lateral arms 14. Body 12 comprises an elongate shell-like structure of 
substantially greater height than width, with a first or upper end 16 and 
a second or lower end 18 and with elongate edges 20. The longitudinal axis 
of body 12, extending from first end 16 to second end 18 through body 12, 
may be straight, or may be curved through a major portion of its length in 
order to match the curvature of a bicycle wheel as dictated by the system 
of attachment of the bicycle to a carrier rack, and as discussed in more 
detail below. The total height of body 12 along a straight line between 
respective ends 16 and 18 is preferably equal to or slightly greater than 
the height of the uppermost point of a bicycle, in place on a vehicle 
mounted carrier rack, from the vehicle roof or other surface upon which 
the rack is mounted. For most applications the height of body 12 will be 
approximately 34 to 36 inches, though it should be readily understood that 
the height may be adjusted as necessary for various bicycle and carrier 
rack designs. In the preferred embodiments of the invention the device is 
provided in standardized heights to correspond to standard bicycle frame 
sizes, but in an alternative embodiment body 12 may be adapted to be 
shortened by the user to match a specific bicycle. Adaptation for user 
adjustment may be achieved by utilizing a material of construction for 
body 12 which is suitable for cutting perpendicular to the longitudinal 
axis of body 12 without material fracture, or by forming body 12 with at 
least one score line across the width of body 12 near either or both ends 
thereof so that a user may readily break or cut away one or more small 
segments of body 12 from either or both ends to adjust its length. Such 
score lines, if used, may be formed during the formation of body 12, or 
may be incised after such formation. 
The width of body 12 is preferably slightly greater than the distance of 
lateral extension of the bicycle frame and closely mounted components of 
the bicycle across the longitudinal axis of the bicycle to be shielded. In 
the preferred embodiments of the device of the invention the width of body 
12 is less than the full lateral extension of the bicycle handlebars and 
handlebar mounted components such as brake levers, which are shielded by 
arms 14, and of the pedals, but is greater than the full lateral extension 
of most other components such as chain sprocket, drive gears, shift 
levers, brake calipers, and deraileur apparatus. With the preferred width 
relationship body 12 directly shields such components closely mounted to 
the bicycle frame, which are the components most sensitive to damage oz 
adjustment disturbance, from impact of objects approaching the bicycle on 
a line parallel to the line of travel of the transport vehicle upon which 
the bicycle is carried. 
It is preferred that the width of body 12 be minimized, consistent with the 
function of providing the direct shielding referred to above, in order to 
minimize its frontal surface area and thus the aerodynamic drag associated 
with device 10. In typical bicycle construction, components mounted on the 
upper part of the frame extend outward a lesser distance than components 
mounted on the lower part of the frame. Accordingly, it is preferred that 
the width of body 12 be greater through the lower portion of the length of 
body 12 than through the upper portion, generally as indicated in FIG. 2. 
Body 12 may be configured as shown in FIG. 2, with the area of increased 
width intermediate ends 16 and 18, or the area of increased width may 
extend fully to lower end 18 without departing from the scope of the 
invention. 
The cross-sectional configuration of body 12 defines a symmetrical curve as 
illustrated in FIG. 3, creating a concave inner surface 22 and a convex 
outer surface 24. During use of device 10, the flow of air impinging on 
outer surface 24 is smoothly divided to flow over surface 24 past edges 
20. In the preferred embodiments of device 10 the curvature is a generally 
semi-circular arc with the arc centered on the longitudinal axis of the 
bicycle with device 10 in place thereon, but the curve may alternatively 
describe other forms, such as a parabolic section, if desired. In a 
further alternative structure within the scope of the invention, body 12 
could be formed with an angular cross-sectional configuration with two 
generally planar halves intersecting at the longitudinal midline of body 
12 centered between edges 20. 
In the preferred embodiments of device 10, body 12 is flared outwardly 
through a flared area 26 extending along and slightly inward from each of 
edges 20, as illustrated in FIG. 3. Air flowing over outer surface 24 of 
body 12 is deflected outwardly from the longitudinal axis of the bicycle 
as the flow of air passes over flared areas 26, creating an envelope of 
relatively still air through which the bicycle moves as the transport 
vehicle and attached bicycle move forward along their line of travel. The 
effective flow path of air around the bicycle created by the combination 
of convex surface 24 and flared areas 26 is illustrated in FIG. 4, in 
which the approximate boundary between the area of relatively still air 
and the more rapidly moving air is indicated by lines 28. Because the 
bicycle is moving in an envelope or area of relatively still air, wind 
noise and drag associated with turbulence created by the irregular flow of 
air over and around the bicycle frame and components is substantially 
reduced. 
Arms 14 of device 10 comprise elongate bodies of the same general 
cross-sectional configuration as body 12, interconnected at one end to and 
extending outwardly from body 12 in opposed paired relationship across the 
longitudinal axis of body 12. In the preferred embodiments of device 10, 
each of arms 14 is interconnected to body 12 with at least one edge of 
each arm 14 aligned with a respective edge 20 of body 12. Arms 14 are 
configured to match the front profile of the handlebars of the bicycle 
with which device 10 is to be used, and are positioned on body 12 so as to 
intercede in the air stream immediately in front of such handlebars with 
device 10 in place and prepared for use. Arms 14 function to directly 
shield the bicycle handlebars and components mounted thereon, such as 
brake levers, from foreign objects in the air stream impinging against 
arms 14 during transportation of the bicycle. 
In the preferred embodiments of device 10, arms 14 are firmly 
interconnected to body 12 in fixed positions, such that the bicycle 
handlebars nest at least partially within the concavity formed by the 
curvature of arms 14, and arms 14 are disposed such that the 
cross-sectional curvature of the arms is centered in the air flow against 
the arms during transportation of the bicycle. In alternative embodiments, 
arms 14 may be adapted to be adjustable in longitudinal disposition along 
the length of body 12 so as to allow the user to adapt their position to 
accommodate different bicycles. Arms 14 may be made adjustable by means of 
one or more curved members interconnected between the proximal ends of the 
two arms, with the curvature of such member or members matching the 
cross-sectional curvature of body 12 including similarly flared areas 40 
along edges 38 thereof, and with the interconnection of arms 14 to body 12 
made through such curved member or members by conventional means such as 
bolts and nuts or snaps. 
Device 10 further includes means of attaching the device to the bicycle 
with which it is to be used or, alternatively, to the bicycle and carrier 
rack or to the carrier rack alone. It is preferred that device 10 be 
attached directly to the bicycle, and such attachment means preferably 
comprise a plurality of elongate straps each interconnected at one end to 
body 12 and arms 14. In attaching device 10 to a bicycle, device 10 is 
positioned with the handlebars at least partially nested in arms 14 and 
body 12 centered immediately in front of the bicycle, at least one strap 
interconnected to body 12 between its midpoint and lower end 18 is passed 
around a portion of the bicycle and secured, and at least one strap above 
the midpoint of device 10 is passed around a portion of the bicycle and 
secured. The upper attachment means may be a single strap interconnected 
to body 12 to be passed around, for example, the handlebar stem, or may be 
a pair of straps with each interconnected to a different one of arms 14 to 
be passed around the handlebars. The straps may be elastic or non-elastic, 
and may be secured by any convenient conventional means, such as buckles, 
snaps, or interlocking hooks and loops. 
Alternatively, device 10 may be adapted to be attached to the carrier rack 
upon which the bicycle is to be carried. In one such approach, lower end 
18 of body 12 may be pivotally interconnected to the carrier rack such 
that device 10 is pivotable forward and backward in the line of travel of 
the vehicle on which the carrier rack is mounted. With that arrangement, 
device 10 can be pivoted forward, the bicycle attached to the rack, and 
device 10 pivoted into its transportation position and secured. 
Bicycles are produced in several different styles and handlebar 
arrangements to accommodate various uses and rider preferences, and 
bicycle carrier racks are also produced with differing systems of 
attaching bicycles to the racks. The device of the invention is readily 
adaptable, within the scope of the invention, for use with different 
bicycle styles and with different carrier rack attachment systems. Several 
examples of such adaptations are described below, but it should be 
understood that other adaptations and combinations of the adaptations used 
as examples may readily be made from the disclosure provided herein. 
Bicycle configurations commonly differ primarily in the configuration and 
placement of handlebars, with two styles seeming to predominate. The first 
is generally referred to as a racing or touring style, in which the handle 
bars extend horizontally from the stem and then curve downward and 
backward, while in the second style, often referred to as a mountain bike 
style, the handlebars extend horizontally but have no downward curve. The 
embodiment of device 10 illustrated in FIGS. 1, 2, and 6 is designed for 
use with the racing or touring style handlebars, and the embodiment 
illustrated in FIG. 5 is adapted for the mountain bike style. 
The variations in carrier rack systems are more extensive, differing 
primarily in the orientation of the bicycle on the carrier rack and in 
whether the bicycle is mounted with the front wheel in place or removed. 
Various examples, while not exhaustive, include the following: 1. 
forward-facing, upright, front-wheel-off; 2. forward-facing, upright, 
front-wheel-on; 3. forward-facing, inverted, front-wheel-on; 4. 
rear-facing, upright, rear-wheel-on; and 5. rear-facing, inverted, 
rear-wheel-on. The principal adaptation of device 10 for accommodation of 
each of the various mounting systems relates to modification of the 
longitudinal configuration of body 12, though the position of arms 14 on 
body 12 may also require some adaptation. 
Referring to the drawings, the basic embodiment illustrated in FIGS. 1, 2, 
and 6 is most suitable for use with the mounting system of example 1. The 
adaptation illustrated in FIG. 7 is suitable for use with the mounting 
system of example 2 and with the mounting system of example 4, and the 
adaptation illustrated in FIG. 8 is suitable for use with the mounting 
systems of examples 3 and 5. 
In order to ensure the stability of the adaptations of device 10 in which 
body 12 is longitudinally curved to be received over one of the wheels of 
the bicycle mounted over the carrier rack, and especially with mounting 
systems in which the bicycle is mounted in a rear-facing configuration 
where the bicycle handlebars are not in direct contact with arms 14, it is 
preferred that body 12 be adapted to mate in a nesting relationship with 
the tire of the bicycle wheel over which it is to be received. In the 
preferred approach, illustrated in FIG. 9, body 12 includes an elongate 
dome 30 centered between edges 20 and extending outwardly from surface 24 
a sufficient distance to receive a portion of tire 32 in a stable nesting 
relationship. Dome 30, which extends longitudinally through the portion of 
body 12 that contacts the tire of the bicycle wheel, is slightly wider 
than tire 32 so as to allow a portion of tire 32 to be received therein. 
In an alternative approach, illustrated in FIG. 10, at least one slot 34, 
to receive a portion of tire 32, is formed along inner surface 22 of body 
12 and centered between edges 20 of body 12. Each slot 34 may be formed by 
interconnection of a pair of formed blocks 36 to surface 22 in opposed 
separated relationship as shown in FIG. 10, or by other convenient means 
such as a pair of opposed tabs extending from surface 22 into the 
concavity of body 12. 
The foregoing description of the preferred embodiments of the device of the 
invention, and of various examples of alternative embodiments and 
adaptations, is illustrative and not for purposes of limitation of the 
full scope of the invention. The device of the invention is susceptible to 
various other modifications and adaptations without departing from the 
scope and spirit of the invention as claimed.