Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The invention relates to a triple mirror wheel, that is, an
optical meahanical component in which triple mirrors are mounted
in alternatingly 180 offset manner on a wheel circumference.
More particularly, it relates to a method for the manufacture
thereof. Such a component is disclosed in West German Patent
application P 37 08 883.1 published September 29, 1988.
The manufacture of such mirror wheels is difficult. The
wheel is optically suitable only when the three surfaces of the
individual triple mirrors intersect with absolute sharpness.
When the surfaces do not so intersect, and when therefore the
three edges of intersections exhibit roundings, then, as~the
light beams transit from one surface to the adjacent one, beam
failure takes place which is the more pronounced the larger the
radius of curvature of the edges.
Having in mind the limitations of the prior art, it is an
object of a broad aspect of the present invention to provide a
method for producing a triple mirror wheel where the individual
triple mirrors have sharp edges.
According to one broad aspect of this invention, a triple
mirror wheel having a plurality of adjacent triple mirrors
positioned about an axis is prepared by the steps of:
positioning a first polygonal ring along the axis, the polygonal
ring having a plurality of adjacent mirror surfaces positioned
about the axis; placing a core of the triple mirror wheel along
the axis and adjacent to the first polygonal ring, the core
comprising a plurality of reflective sides and an annular series
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of V-shaped ridges which are formed by intersections between the
reflective sides, wherein aircumferentially adjacent ones of the
V-shaped ridges are oriented to face in opposite axial directions
of the triple mirror wheel, wherein circumferentially alternate
ones of the V-shaped ridges which face toward the first polygonal
ring are caused to align with the plurality of adjacent mirror
surfaces of the first polygonal ring as the core is placed
adjacent to the first polygonal ring, thereby forming a
corresponding first number of triplet mirrors; securing the first
polygonal ring to the core; positioning a second polygonal ring
along the axis and adjacent to a side of the core opposite to the
first polygonal ring, the second ring comprising a plurality of
adjacent mirror surfaces positioned about the axis, the adjacent
mirror surfaces positioned about the axis, the adjacent mirror
surface of the second polygonal ring aligning with
circumferentially alternate ones of the V-shaped ridges which
face toward the second polygonal mirror; and securing the second
polygonal ring to the core.
By another aspect of this invention, a triple mirror wheel
is provided comprising: a first polygonal ring having a plurality
of adjacent mirror surfaces on a first side thereof, the
reflective surfaces being positioned about an axis; a core
secured to the first side of the first polygonal ring along the
axis, the axis, the core comprising a plurality of adjacent
ridges, the adjacent ridges being offset 180 one to the other,
alternate.ridges aligning with the plurality of adjacent mirror
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surfaces of the first polygonal ring to form a first
corresponding number of triplet mirrors; a second polygonal ring
having a plurality of adjacent reflective surfaces on a first
side thereof, the second polygonal ring secured along the axis
to a side of the core opposite the first polygonal ring, adjacent
mirror surfaces of the second polygonal ring aligning with other
alternate ridges of the core, and forming a second corresponding
number of triplet mirrors.
In the accompanying drawings,
Fig. 1 is a side elevational view of the triple mirror
wheel;
Fig. 2 is a perspective view of the triple mirror wheel of
Fig. l;
Fig. 3 is a perspective view of the inside surface of a
polygonal ring cooperating with the triple mirror wheel;
Fig. 4 is a perspective view of the outside surface of the
polygonal ring of Fig. 3;
Fig. 5 is a perspective view showing the body of the tri ~e
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mirror wheel and two polygonal rings on a shaft in their half
assembled state; and
Fig. 6 is a perspective view showing the triple mirror wheel
in the fully assembled state on a shaft.
Fig. 1 shows the hub 1 of the core 2 of the triple mirror
wheel, (See Fig. 6). In this manner, one obtains ridges 6
rotated by 180 which are always adjacent on one side 3. The
edges between these sides 3, that is the ridges 6, can be made
extremely sharp because this geometry permits clear access from
all sides to a suitable tool, for instance a milling cutter.
Thread holes 7 are shown in Fig. 2 whereby the polygonal
rings 4 ~only one of which being seen) may be secured to the top
and bottom of the triple mirror wheel. Bolt holes 8 in the hub 1
are available for connection to means (not shown) for rotating
the triple mirror wheel.
Fig. 3 shows the inside of a polygon ring 4 with smooth
polygonal facet~ 5 of which the dimensions coincide with the
mis~ing third sides on the core 2 of Fig. 1 of the triple mirrors
to be made individually. Again, the~e polygon surfaces can be
made planar with extreme accuracy. Bolt holes 9 (See Fig. 4)
facilitate securing the polygon rings 4 onto both sides of the
core 2 with bolts or screws (not shown).
Fig. 5 show~ the de~cribed three individual components (one
core 2 and two polygonal rings 4) slipped onto a shaft 10 and in
the partly a~embled state. Fig. 6 shows these three components
fully assembled, to form the triple mirror wheel 9, the two
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polygon rings 4 being rigidly joined to, i.e., screwed onto, the
core 2.
It is noted that this method permits the production of a
triple mirror wheel 9 comprising triple mirrors each time rotated
by 180 with exceedingly sharp edges. One edge of each triple
mirror, designated above as the ridge 6, can be made sharp, as
already mentioned above, because of the clear access allowed to a
tool, on core 2, whereas the two other edges of each triple
mirror are formed by the surfaces of the polygon ring 4 on which
the external edges of the core 2 lie flat and without any
curvature.
