Note: Descriptions are shown in the official language in which they were submitted.
CA 02350446 2008-04-29
PLASTIC MIRROR ASSEMBLY
Background of the Invention
The present invention relates to vehicular mirrors. More particularly, the
present invention concerns plastic vehicular mirror assemblies. Even more
particularly, the present invention relates to plastic vehicular mirror
assemblies
and methods of manufacture therefor.
Prior Art
As is known to those skilled in the art to which the present invention
pertains, the use of plastic mirrors, both interiorly and exteriorly, in
association
with automotive vehicles has been well known. Generally, such mirrors,
especially
exterior school bus mirrors, comprise a plastic housing to which is secured a
plastic
silverized reflective surface or lens. Usually, the lens is formed from a
suitable
plastic material onto which is deposited a silverized surface. The silverized
surface
defines a reflective surface. Also, the lens has a curvature imparted thereto
in order
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to achieve the desired or necessary field of view when the mirror assembly,
the lens
and housing is installed on the vehicle.
The other component of the assembly, the mirror housing or backing, is a
molded plastic part in which is housed mounting bracketry; heating elements,
remote control operation electronics, lighting accessories and the like. As
explained
below, typically, the housing is manufactured with a lip or shoulder on or in
which
is seated an edge portion of the lens. A rubber gasket is fitted to the
housing to
finish the assembly. The gasket covers any unsightly appearance where the lens
is
mated to the housing, as well as sealing off the housing interior from water
due to
rain, car washing, snow and the like.
In manufacturing such plastic mirror assemblies, it is to be appreciated that
they offer the advantage of being cheaper to manufacture than those assemblies
which utilize glass lenses. Also, plastic lenses are more durable than glass
lenses
and less susceptible to breakage. However, in manufacturing the plastic mirror
assemblies it is necessary to glue the lens to the housing. This assembly step
is a
time-consuming manual task which adds to the cost of manufacture. As discussed
below, the present invention provides a means for eliminating the gluing of
the lens
to the housing.
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Summary of the Invention
In accordance with the present invention, there is provided a mirror head
assembly or mirror which is particularly adapted for use as an exterior
automotive
mirror assembly. The mirror hereof, generally, comprises a housing and a lens,
the
lens and housing, each being formed from a suitable plastic material.
The housing is provided with at least one, and, preferably, a plurality of
slots
disposed thereon.
The lens or mirror has a plurality of peripheral upstanding outwardly-
projecting tabs, each one tab being associated with a slot formed in the
housing.
The lens has a sufficient flexibility to enable the tabs to be "snap fitted"
into their
associated slots. In this manner, there is provided an easily assembleable
mirror
head and assembly which can be easily repaired.
In another aspect hereof, the present invention provides a method of
producing a mirror head assembly which, generally, comprises:
(a) forming a mirror housing, the mirror housing including an upstanding
peripheral wall, at least one slot being formed in the peripheral wall, and
(b) providing a lens, the lens having at least one tab extending from the
edge of the element, the tab being dimensioned to fit within the slot.
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According to an aspect of the present invention there is provided a
vehicular mirror head assembly for a vehicle, the vehicular mirror head
assembly
comprising:
a housing member adapted for said vehicle, said housing member being made of
a plastic material and having a substantially solid rear portion and an open
front
portion, said open front portion having a perimetral wall defining an opening;
said housing member having a ledge member formed around said perimetral wall
of said open front portion, said ledge member having a plurality of slotted
apertures positioned around the perimeter of said open front portion;
a lens member positioned in said opening, said lens member being made of a
plastic material and having a size and shape substantially the same as said
open
front portion of said housing member, said lens member having a reflective
surface thereon and having a plurality of tab members extending outwardly in
the
plane of the reflective surface from an edge thereof, said tab members
positioned
in and mated with said slotted apertures; and
a gasket member, said gasket member made from an elastomeric material and
positioned on said ledge member around the perimeter of said open front
portion,
said gasket member surrounding said housing member and sealing said slotted
apertures from water and other environmental matters.
According to another aspect of the present invention there is provided a
method of manufacturing a vehicular mirror head assembly for a vehicle, the
method comprising:
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(a) providing a housing member adapted for said vehicle, said housing member
being made of a plastic material and having a substantially solid rear portion
and
an open front portion, said open front portion having a perimetral wall
defining an
opening;
said housing member having a ledge member formed around said perimetral wall
of said open front portion, said ledge member having a plurality of slotted
apertures positioned around the perimeter of said open front portion;
(b) providing a lens member, said lens member being made of a plastic material
and having a size and shape substantially the same as said open front portion
of
said housing member, said lens member having a reflective surface thereon and
having a'plurality of tab members extending outwardly in the plane of the
reflective surface from an edge thereof,
(c) assembling said lens member onto said housing member, said assembly
comprising positioning said lens member in said open front portion of said
housing member and positioning said tab members in said slotted apertures;
(d) providing a gasket member made from an elastomeric material; and
(e) assembling said gasket member on said housing member, said gasket member
being positioned on said ledge member and covering said slotted apertures.
For a more complete understanding of the present invention, reference is
made to the following detailed description and accompanying drawing. In the
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drawing like reference characters refer to like parts throughout the several
views in
which:
Brief Description of the Drawing
Figure 1 is a perspective rear view of a plastic vehicular mirror assembly in
accordance with the present invention;
Figure 2 is a front view of a plastic reflective lens for use in the present
invention;
Figure 3 is a front elevational view of a mirror housing in accordance with
the present invention;
Figure 4 is a exploded perspective partial view of a lens and housing in
accordance herewith in an unassembled state, and
Figure 5 is a view similar to Fig. 4, but showing the lens and housing in an
assembled.
Description of the Preferred Embodiment
Now, and with reference to the drawing, there is depicted herein a vehicular
mirror head assembly in accordance herewith and, generally, denoted at 10. The
assembly 10 comprises a housing 12, a lens 14 and means for snap-fitting the
lens
to the housing.
As shown, the housing 12 comprises a plastic body 16 defining a shell 18
having an open end 20. The shell 18 is an irregularly or regularly shaped
member
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having a parametric edge or shoulder 22 which bounds the end 20. Preferably,
an
upstanding wall 24 extends upwardly from the shoulder 22 and terminates at an
edge 26. The shoulder 22 defines a seat or ledge for the lens 14 as described
below.
In accordance herewith, and as shown, at least one and, preferably, a
plurality of openings or slot 28 are provided in the wall 24. Where a
plurality of
openings are provided, they are circumferentially positioned on the wall 24
about
the periphery of the open end 20. As will become apparent hereinafter the
opening(s) or slot(s) 28 cooperate with complementary structure on the lens 14
of
the assembly 10 to provide the means for snap-fitting the lens to the housing.
The lens 14 has a front surface 30 and a rear surface (not shown). The rear
surface has a reflective material deposited thereon for creating a reflective
surface
for viewing objects therein. Although not critical hereto, it should be noted
that
ordinarily the lens has a pre-determined curvature imparted thereto during
manufacture, be it convex, elliptical, etc for providing the requisite viewing
area or
field of view. The lens has an edge 36 defined therearound. Regardless of the
configuration of the lens, at least one tab 34 and, preferably, a plurality of
tabs 34
are disposed at the edge 36 of the lens 14. Preferably, the tab 34 is
integrally
formed with the lens 14 and extend(s) outwardly from the edge 36.
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Preferably there is one tab 34 per slot or opening, although there may be less
tabs than openings or vice versa.
The tabs are circumferentially disposed about the perimeter of the lens and
are dimensioned to snap fit into their associated openings 28. The cooperation
between the tabs and openings enables a mechanical interconnection
therebetween
that eliminates the need for gluing the lens to the housing.
In creating a mirror assembly by the practice of the present invention the
lens 14 is brought into contact with the housing 12 such that the perimetral
area of
the lens proximate the edge 36 seats on or is connected with the ledge 20. The
lens
14 is oriented such that the tab(s) is aligned with an associated opening or
openings. The tab(s) 34 is snap-fitted into its associated opening(s) 28 to,
thus,
mount or connect the lens to the housing. It is thus seen that the tab and
opening or
plurality thereof cooperate to define means for snap-fitting the lens to the
housing.
Thus, the mirror hereof is assembled by a method of providing complementary
tabs
and openings on the lens and housing, respectively, and thereafter snap-
fitting the
lens and housing together by inserting the tabs into associated slots.
After mounting the lens to the housing, a gasket (not shown) is fitted onto
the
housing 12 at the edge 26 of the wall 24 to finish the assembly 10.
It should be noted and as shown in the drawing, the height wall 24 has a
height which is greater than the thickness of the lens to ensure that the slot
is
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dimensional such that the tab is nested between the lower end and upper end of
the
wall.
It is apparent from the preceding that the present invention provides an
efficient and effective way for assembling plastic mirrors that eliminates the
need
for gluing the lens and housing together. The present invention is
particularly
advantageous in that the tabs can be formed during the molding of the lens
and,
similarly, the openings can be pre-formed during the molding of the housing.
In use, the mirror head assembly is affixed to suitable bracketry well known
to the skilled artisan. Such bracketry includes a mounting shaft having one
end
connected to the housing and the other end secured to the vehicle through a
suitable
mount adapted for that portion of the vehicle to which the mirror head
assembly is
to be located.
Having, thus, described the invention, what is claimed is:
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