U.S. patent application number 11/152205 was filed with the patent office on 2006-01-19 for optical sight with rangefinder and assembly method for the same.
This patent application is currently assigned to Asia Optical Co., Inc.. Invention is credited to Shang-Yung Liang, Chen-Yeh Lin.
Application Number | 20060010762 11/152205 |
Document ID | / |
Family ID | 35597924 |
Filed Date | 2006-01-19 |
United States Patent
Application |
20060010762 |
Kind Code |
A1 |
Lin; Chen-Yeh ; et
al. |
January 19, 2006 |
Optical sight with rangefinder and assembly method for the same
Abstract
The present invention provides an optical sight with rangefinder
and assembly method thereof. The optical sight comprises an erector
lens unit, a photoelectric rangefinding unit, a barrel, an
objective lens unit, a plurality of adjusting elements, a power
supply unit and an eyepiece lens unit disposed on the barrel. The
photoelectric rangefinding unit includes a laser emitter, a laser
receiver and a range indicator. A plurality of openings are formed
on sidewall of the barrel corresponding to the positions of the
laser emitter, laser receiver and range indicator for conducting
the cavity to outside the barrel. The assembly method comprises the
steps of: assembling the erector lens unit, the photoelectric
rangefinding unit and the barrel together, then connecting an
objective lens unit and mounting a plurality of adjusting elements,
adjusting the objective lens unit and mounting the adjusting
elements and the power supply unit, adjusting the focus of the
laser emitter and the laser receiver and adjusting the position of
the range indicator through the openings formed on the barrel for
complying with the requirement of photoelectric rangefinding
performance. The assembly method of the optical sight according to
the present invention can be adjusted after all elements are
assembled. The assembly method of the optical sight according to
the present invention can be used to reduce the adjusting times and
prevent unnecessary disassemblies and re-assemblies for simplifying
the assembly process and improving the yield rate and the
productibility of the optical sight.
Inventors: |
Lin; Chen-Yeh; (Taichung,
TW) ; Liang; Shang-Yung; (Taichung, TW) |
Correspondence
Address: |
TROXELL LAW OFFICE PLLC
SUITE 1404
5205 LEESBURG PIKE
FALLS CHURCH
VA
22041
US
|
Assignee: |
Asia Optical Co., Inc.
|
Family ID: |
35597924 |
Appl. No.: |
11/152205 |
Filed: |
June 15, 2005 |
Current U.S.
Class: |
42/142 |
Current CPC
Class: |
F41G 1/38 20130101 |
Class at
Publication: |
042/142 |
International
Class: |
F41G 1/00 20060101
F41G001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 17, 2004 |
TW |
093117443 |
Claims
1. An optical sight with rangefinder, which comprises: a barrel
defined with a cavity extended through therein axially; a
photoelectric rangefinding unit disposed in the cavity of the
barrel, having a laser emitter, a laser receiver and a range
indicator, and defined with a tunnel; an erector lens unit disposed
in the tunnel of the photoelectric rangefinding unit, having a
reference mark for aiming; an objective lens unit disposed on one
end of the barrel; an eyepiece lens unit disposed on the other end
of the barrel; an adjusting element disposed on the outside surface
of the barrel and extended into the barrel partially, corresponding
to at least one of the objective lens unit, the photoelectric
rangefinding unit and the erector lens unit thereby adjusting the
relative positions of the objective lens unit, the photoelectric
rangefinding unit and/or the erector lens unit; and a power supply
unit disposed on the barrel, providing an electrical power to
generate the rangefinding function; wherein the sidewall of the
barrel is formed with a plurality of openings corresponding to the
positions of the laser emitter, laser receiver and/or range
indicator of the photoelectric rangefinding unit.
2. The optical sight with rangefinder as claimed in claim 1 wherein
the photoelectric rangefinding unit comprises a reflecting prism
collocating with the laser emitter, the laser receiver and the
range indicator.
3. The optical sight with rangefinder as claimed in claim 2 wherein
the reflecting prism includes a reflecting surface for reflecting a
light with a predetermined wavelength and allowing other light with
other wavelengths to pass.
4. The optical sight with rangefinder as claimed in claim 1 further
comprising a reticle as the reference mark for aiming.
5. The optical sight with rangefinder as claimed in claim 4 wherein
the reticle is positioned at one of the image plane of the
objective lens unit and the image plane of the erector lens
unit.
6. The optical sight with rangefinder as claimed in claim 5 wherein
the emitting beam of the laser emitter is aligned with the center
of the reticle.
7. The optical sight with rangefinder as claimed in claim 6 wherein
the receiving beam of the laser receiver is aligned with the center
of the reticle.
8. The optical sight with rangefinder as claimed in claim 1 wherein
the range indicator projects an image on the image plane of the
objective lens unit or the image plane of the erector lens
unit.
9. The optical sight with rangefinder as claimed in claim 1 wherein
the barrel comprises a plurality of sealing sheets utilized to seal
the openings of the barrel after assembly and adjustment of the
optical sight.
10. The optical sight with rangefinder as claimed in claim 1
further comprising an optical filter positioned in front of the
objective lens unit.
11. A method for assembling an optical sight with rangefinder,
comprising the steps of: assembling an erector lens unit, a
photoelectric rangefinding unit, a barrel formed with a plurality
of openings, an objective lens unit, and an adjusting element into
a first assembly; adjusting the objective lens unit and the erector
lens unit of the first assembly to meet the requirements of the
parallax and the point of impact performances; adjusting any one of
a laser emitter, a laser receiver and a range indicator of the
photoelectric rangefinding unit to meet the requirement of the
photoelectric rangefinding performance; assembling an eyepiece lens
unit to an end of the barrel; and sealing the openings of the
barrel thereby completing assembly of the optical sight with
rangefinder.
12. The method for assembling an optical sight with rangefinder as
claimed in claim 11, further comprising a step of adjusting the
position of a reticle to reach the image plane of the objective
lens unit or the image plane of erector lens unit and then fixing
the reticle.
13. The method for assembling an optical sight with rangefinder as
claimed in claim 12 wherein the requirement of the parallax
performance is that there is no parallax at 100 yards, and the
requirement of the point of impact performance is that the point of
impact is lower than 1 MOA (minute of angle).
14. The method for assembling an optical sight with rangefinder as
claimed in claim 12 wherein the adjustment of the laser emitter is
implemented through a first opening of the barrel, to align the
emitting beam of the laser emitter with the center of the
reticle.
15. The method for assembling an optical sight with rangefinder as
claimed in claim 12 wherein the adjustment of the laser receiver is
implemented through a second opening of the barrel, to align the
receiving beam of the laser receiver with the center of the
reticle.
16. The method for assembling an optical sight with rangefinder as
claimed in claim 11 wherein the adjustment of the range indicator
is implemented through a third opening of the barrel, to adjust the
position of the characters displayed by the range indicator.
17. The method for assembling an optical sight with rangefinder as
claimed in claim 12, further comprising a step of mounting a power
supply assembly on the barrel.
18. The method for assembling an optical sight with rangefinder as
claimed in claim 17, further comprising a quality test procedure
before assembling the optical sight, including an optical
performance test, a photoelectric rangefinding performance test, an
impact strength test and an air-sealing performance test.
19. The method for assembling an optical sight with rangefinder as
claimed in claim 17, further comprising a step of assembling an
optical filter to cover the objective lens unit.
20. An optical sight with rangefinder, comprising a barrel, a
photoelectric rangefinding unit, an objective lens unit, an
eyepiece lens unit and an adjusting elements wherein the barrel is
a hollow barrel provided with a cavity extended through therein
axially, the photoelectric rangefinding unit is assembled into the
cavity of the barrel, a plurality of openings are formed on the
sidewall of the barrel for adjusting the photoelectric rangefinding
unit without disassembling the optical sight.
21. The optical sight with rangefinder as claimed in claim 20
wherein the barrel further comprises a plurality of sealing sheets
utilized to seal the openings of the barrel after assembly and
adjustment of the optical sight.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an optical sight and
assembly method for the same, and more specifically, to a
telescopic optical sight capable of rangefinding and assembly
method for the same.
[0003] 2. The Related Art
[0004] In general, an optical system of conventional telescopic
sight comprises an objective lens assembly, an erector lens
assembly, an eyepiece lens assembly and a scale board with a
reticle. The scale board is marked with a rough rangefinding scale.
A shooter can rapidly estimate the range to a target by referring
to the rangefinding scale. Therefore, such conventional telescopic
sight may be used as a simple rangefinder.
[0005] However, the range estimation of conventional telescopic
sight is mostly depended on the user's experience that may likely
bring a larger tolerance. Accordingly, a telescopic sight
progressively takes the precise shooting and rangefinding fields. A
conventional telescopic sight has been disclosed in U.S. Pat. No.
5,771,623 issued on Jun. 30, 1998. The conventional telescopic
sight mainly comprises an objective lens assembly, a laser
transmitter (like a laser diode, LD), a laser receiver (like an
avalanche photoelectric diode, APD), a range indicator (like a
light emitting diode, LED) and three sets of prisms, erector lens
unit and eyepiece lens unit which are provided with a dichroic
coating. The laser transmitter and the laser receiver both
constitute a rangefinder of the telescopic sight. The laser
rangefinder operates on a principle of measuring a travel period
from emission of a laser pulse or laser pulse sequence by the laser
transmitter, via pulse reflection with a target aimed at, to a
reflected pulse reception by the laser receiver. One half of the
value that this travel period is multiplied by the light speed
constant yields the distance between the rangefinder and target.
The distance calculation is performed by a calculation device or
program disposed within the telescopic sight.
[0006] Generally, several components adapted for conventional
telescopic sight, like the objective lens unit, erector lens unit,
rangefinding device and eyepiece lens unit, are modularized,
individually, and each one is assembled and adjusted respectively
into a barrel and then adjusted again after assembled. As the
conventional telescopic sight disclosed in U.S. Pat. No. 5,771,623,
the erector lens unit thereof is firstly assembled generally, and
then fixed on a fabrication fixture for adjusting a position of a
reticle to reach a first image plane. Thereafter, the erector lens
unit is mounted within a laser rangefinding unit, and the
photoelectric rangefinding functions provided with coordination
among the laser transmitter, laser receiver and range indicator are
adjusted. The complete-adjusted laser rangefinding unit, the
objective lens unit, an adjusting mechanism and a power supply unit
are disposed into the barrel, respectively. The parallax of the
objective lens unit is adjusted after assembled. Meanwhile, if any
lens or the reticle becomes contaminated or slanted, each component
should be detached from the barrel for adjusting each component
before assembled again. Eventually, the eyepiece lens unit can be
assembled with the barrel for accomplishing the assembly of the
telescopic sight. A quality control procedure, including an optical
performance inspection, a photoelectric rangefinding performance
inspection, an impact strength inspection and an air-sealing
inspection etc., is processed for the finished telescopic sight. If
there is any performance varied within the need of re-adjusting, as
aforementioned that any lens or the reticle becomes contaminated or
slanted, each component should be detached from the barrel and then
adjusted before assembled again. Obviously, each step in the
assembly of the conventional telescopic sight, i.e. adjusting and
assembling, must be repeated if there is any misstep appearing in
the assembly. Understandingly, the assembly procedure of the
conventional telescopic sight is more complicated and unfavorable
to both the cost and manufacturing.
[0007] For above reasons, it is necessary to provide an optical
sight and an assembly method thereof for simplifying the assembly
procedure and improving the productibility.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide an optical
sight with rangefinder capable of easily facilitating adjustment
during assembling and the quality assurance procedure after
assembled by way of simplifying the assembly procedure and
improving the productibility thereof.
[0009] Another object of the present invention is to provide an
assembly method of an optical sight with rangefinder capable of
facilitating adjustment and the quality assurance procedure after
assembled for reducing re-assembled procedures and improving the
productibility thereof.
[0010] According above objects of the present invention, there is
provided an optical sight with rangefinder comprising an erector
lens unit, a photoelectric rangefinding unit, a barrel, an
objective lens unit, a plurality of adjusting elements, a power
supply unit and an eyepiece lens unit disposed on the barrel. The
photoelectric rangefinding unit includes a laser emitter, a laser
receiver and a range indicator. The photoelectric rangefinding unit
is formed with a tunnel inside passed through therein for
containing the erector lens unit. The barrel is a hollow barrel
which is formed with a cavity passed through therein axially for
containing the erector lens unit. A plurality of openings are
formed on sidewall of the barrel corresponding to the positions of
the laser emitter, laser receiver and range indicator for
conducting the cavity to outside the barrel. The objective lens
unit is disposed on one end of the barrel and the eyepiece lens
unit is disposed on the other end of the barrel. The adjusting
elements are disposed on the barrel corresponding the positions
connected with the objective lens unit for adjusting the status of
the objective lens unit.
[0011] The assembly method of the optical sight in accordance with
the present invention comprises the steps below: [0012] STEP 1:
assembling the erector lens unit, the photoelectric rangefinding
unit and the barrel formed with a plurality of openings, an
objective lens unit and an adjusting element into a first assembly;
[0013] STEP 2: adjusting the objective lens unit and the erector
lens unit of said first assembly to meet the requirements of the
parallax and the point of impact (POI) performances; [0014] STEP 3:
adjusting the position of the reticle to reach the image plane of
the objective lens unit or the image plane of erector lens unit and
then fixing the position of the reticle; [0015] STEP 4: adjusting
the focus of the laser emitter and the laser receiver and adjusting
the position of the range indicator of the first assembly to meet
the requirement of the photoelectric rangefinding performance;
[0016] STEP 5: assembling the eyepiece lens unit to an end of the
barrel of the first assembly; [0017] STEP 6: assembling the optical
filtering unit to position in front of the objective lens unit;
[0018] STEP 7: a quality test procedure will be implemented after
aforementioned assembling steps. The quality test procedure
includes an optical performance test, a photoelectric rangefinding
performance test, an impact strength test and an air-sealing
performance test. The assembling process will be returned to step 1
if any defect found in the quality test procedure; [0019] STEP 8:
sealing the openings of the barrel by utilizing a plurality of
sealing sheets thereby completing assembly of the optical sight
with rangefinder.
[0020] In contrast to the prior art, the optical sight according to
the present invention comprises the openings disposed on sidewall
of the barrel corresponding to the positions of the laser emitter,
laser receiver and the range indicator for easily facilitating the
adjustment of each element. The optical sight according to the
present invention is capable of preventing unnecessary
disassemblies and re-assemblies for saving the total assembled time
and reducing the number of defective products and the cost of
production. The assembly method of the optical sight according to
the present invention can be adjusted after all elements are
assembled. The assembly method of the optical sight according to
the present invention can be used to reduce the adjusting times and
prevent unnecessary disassemblies and re-assemblies for simplifying
the assembly process and improving the yield rate and the
productibility of the laser sight.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The present invention will be apparent to those skilled in
the art by reading the following description of preferred
embodiments thereof, with reference to the attached drawings, in
which:
[0022] FIG. 1 is an exploded view of an optical sight with
rangefinder in accordance with the present invention;
[0023] FIG. 2 is a perspective view of an objective lens unit and a
photoelectric rangefinding unit before assembled;
[0024] FIG. 3 is a perspective view of the assembled optical sight
in accordance with the present invention;
[0025] FIG. 4 is a right-side view of the optical sight in
accordance with the present invention illustrating that the
adjustment of the position where the focus of a laser emitter lay
in;
[0026] FIG. 5 is a magnified view of the optical sight shown in
FIG. 4 illustrating that the adjustment of the position where the
focus of the laser emitter lay in;
[0027] FIG. 6 is a left-side view of the optical sight in
accordance with the present invention illustrating that the
adjustment of the position where the focus of a laser receiver lay
in;
[0028] FIG. 7 is a magnified view of the optical sight shown in
FIG. 6 illustrating that the adjustment of the position where the
focus of the laser receiver lay in;
[0029] FIG. 8 is an upward view of the optical sight in accordance
with the present invention illustrating that the adjustment of the
position where the focus of a range indicator lay in; and
[0030] FIG. 9 is a magnified view of the optical sight shown in
FIG. 8 illustrating that the adjustment of the position where the
display focus of the range indicator lay in.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] The present invention will now be described more
specifically with reference to the following embodiments. It is to
be noted that the following description of the preferred
embodiments of the present invention are presented herein for
purpose of illustration and description only and it is not intended
to be exhaustive or to be limited to the precise form
disclosed.
[0032] With reference to FIG. 1, a laser sight according to a
preferred embodiment of the present invention, comprises an erector
lens unit 1, a photoelectric rangefinding unit 2, a barrel 3, an
objective lens unit 4, adjusting elements 5, 51, 52, a power supply
unit 6 disposed on the barrel, an optical filter 7 and an eyepiece
lens unit 8. The erector lens unit 1 is served to invert and revert
the image produced by the objective lens into a normal way and
capable of adjusting the magnification of the optical sight. A
reticle served as a reference cross-hair mark for aiming a target
is disposed within the erector lens unit 1. The photoelectric
rangefinding unit 2 is a hollow barrel formed as an approximately
rectangular shape. A laser emitter 21, a laser receiver 22 and a
range indicator 24 (refer to FIG. 4 to FIG. 9) are contained inside
the photoelectric rangefinding unit 2 and a reflecting prism (not
shown) collocating with the laser emitter 21, the laser receiver 22
and the range indicator 24 is also disposed therein. The reflecting
prism includes a reflecting surface for reflecting a light with a
predetermined wavelength and allowing other light with other
wavelengths to pass. The power supply unit 6 provides an electrical
power to generate the rangefinding function. In addition, the
photoelectric rangefinding unit 2 is formed with a tunnel 20 passed
through therein for containing aforementioned erector lens unit 1.
Generally speaking, in the preferred embodiment according the
present invention, the laser emitter 21 may be a laser diode (LD),
the laser receiver 22 may be an avalanche photoelectric diode (APD)
and the range indicator 23 may be a light emitting diode (LED)
panel.
[0033] Please refer to FIG. 1. The barrel 3 is a hollow barrel. A
cavity 31 is formed inside the barrel 3 and extended through
therein axially for containing aforementioned photoelectric
rangefinding unit 2. A first rectangular opening 33 is formed on a
right sidewall of the barrel 3 corresponding to the position of the
laser emitter 21 of the photoelectric rangefinding unit 2. A second
rectangular opening 32 is formed on a left sidewall of the barrel 3
corresponding to the position of the laser receiver 22 of the
photoelectric rangefinding unit 2. A third rectangular opening 34
is formed on a bottom sidewall of the barrel 3 corresponding to the
position of the range indicator 23 of the photoelectric
rangefinding unit 2. The first, second and third rectangular
opening 33, 32, 34 are used to conduct the cavity 31 to outside the
barrel 3. The assembler or user can adjust the rangefinding
performance of the optical sight through the openings without
detaching the abovementioned elements. Furthermore, a power supply
retainer 30 is formed on the sidewall of the barrel 3 for
containing and fixing the power supply unit 6.
[0034] Please refer to FIG. 1 to FIG. 4. The objective lens unit 4
is disposed on one end of the barrel 3 adjacent to the
photoelectric rangefinding unit 2. The eyepiece lens unit 8 is
disposed on the other end of the barrel 3 adjacent to the erector
lens unit 1. The adjusting element 5 and an adjusting element 52
are respectively disposed on the upside surface and right side
surface of the barrel 3 corresponding the positions connected with
the objective lens unit 4 for adjusting the relative position of
the objective lens unit 4. An adjusting element 51 is disposed on
the left side surface of the barrel 3 approximating to the position
of the second rectangular opening 32 for adjusting the relative
positions of the erector lens unit 1 and the photoelectric
rangefinding unit 2. The optical filter 7 is positioned in front of
the objective lens unit 4 for filtering out the light with specific
wavelength and visible light which is unfavorable to the
observation. The optical filtering lens unit 7 is used to prevent
the defects occurring while laser receiver 22 receiving the reflect
laser light and the user observing.
[0035] Please referring to FIG. 2 and FIG. 3. The assembly method
of the optical sight with rangefinder in accordance with the
present invention comprises the steps below: [0036] STEP 1:
assembling the erector lens unit 1, the photoelectric rangefinding
unit 2 and the barrel 3 with a plurality of openings 32, 33, 34,
the objective lens unit 4 and the adjusting element 5 into a first
assembly; [0037] STEP 2: adjusting the objective lens unit 4 and
the erector lens unit 1 of said first assembly to meet the
requirements of the parallax and the point of impact (POI)
performances; [0038] STEP 3: adjusting the position of the reticle
to reach the image plane of the objective lens unit 4 or the image
plane of erector lens unit 1 and then fixing the position of the
reticle; [0039] STEP 4: adjusting the focus of the laser emitter 21
and the laser receiver 22 and adjusting the position of the range
indicator 23 of the first assembly to meet the requirement of the
photoelectric rangefinding performance; [0040] STEP 5: assembling
the eyepiece lens unit 8 to an end of the barrel of the first
assembly; [0041] STEP 6: assembling the optical filtering unit 7 to
position in front of the objective lens unit 4; [0042] STEP 7: a
quality test procedure will be implemented after aforementioned
assembling steps. The quality test procedure includes an optical
performance test, a photoelectric rangefinding performance test, an
impact strength test and an air-sealing performance test. The
assembling process will be returned to step 1 if any defect found
in the quality test procedure; [0043] STEP 8: sealing the openings
32, 33, 34 of the barrel 3 by utilizing a plurality of sealing
sheets thereby completing assembly of the optical sight with
rangefinder.
[0044] Following the above description, in step 4, the reticle is
positioned at the image plane of the objective lens unit 4 or the
image plane of the erector lens unit 1 (i.e. a first focus plane
which the focus of the objective lens located in and a second focus
plane which the focus of the erector lens unit located in).
Generally speaking, the requirement of the parallax performance of
the optical sight is that there is no parallax at 100 yards, and
the requirement of the POI performance is 1 MOA (minute of angle),
i.e. only a tolerance which below one inch can be allowed between
the high magnification image and low magnification image at 100
yards. The adjustment of the photoelectric rangefinding performance
is mostly implemented by adjusting the positions of the focus of
the laser emitter 21 and laser receiver 22 and the range which the
range indicator indicates. As shown in FIG. 4 and FIG. 5, the
adjustment of the focus of the laser emitter 21 is implemented by
adjusting the emitting beam of the laser emitter 21 to align with
the center of the reticle and adjusting the focus of the laser
emitter 21 to be collinear with the reticle and the focus of the
image plane through the first rectangular opening 33 located in the
right sidewall of the barrel 3. The laser emitter 21 can be
adjusted along three axes toward the forward and rearward
bi-directions (AB direction), the leftward and rightward
bi-directions (CD direction) and the upward and downward
bi-directions (EF direction). As shown in FIG. 6 and FIG. 7, the
adjustment of the focus of the laser receiver 22 is implemented by
adjusting the receiving beam of the laser receiver 22 to align with
the center of the reticle and adjusting the focus of the laser
receiver 22 to be collinear with the reticle and the focus of the
image plane through the second rectangular opening 32 located in
the left sidewall of the barrel 3. The laser receiver 22 can be
adjusted along three axes toward the forward and rearward
bi-directions (AB direction), the leftward and rightward
bi-directions (CD direction) and the upward and downward
bi-directions (EF direction). As shown in FIG. 8 and FIG. 9, the
adjustment of the displaying focus of the range indicator 23 is
implemented by adjusting the position of the characters displayed
in the range indicator 23 and adjusting the displaying focus of the
range indicator 23 to be collinear with the reticle and the focus
of the image plane through the third rectangular opening 34 located
in the bottom sidewall of the barrel 3. The range indicator 23
projects an image on the image plane of the objective lens unit 4
or the image plane of the erector lens unit 1. The range indicator
23 can be adjusted along three axes toward the forward and rearward
bi-directions (AB direction), the leftward and rightward
bi-directions (CD direction) and the upward and downward
bi-directions of elevation (HI direction).
[0045] As a result of that the opening 33, 32, 34 are disposed on
sidewalls of the barrel 3 corresponding to the position of the
laser emitter 21, laser receiver 22 and the range indicator 23, the
adjustment of each element can be simplified to prevent unnecessary
disassemblies and re-assemblies for saving the total assembled time
and reducing the number of defective products and the cost of
production. The assembly method of the optical sight according to
the present invention can be adjusted after all elements are
assembled. The assembly method of the optical sight according to
the present invention can be used to reduce the adjusting times and
prevent unnecessary disassemblies and re-assemblies for simplifying
the assembly process and improving the yield rate and the
productibility of the laser sight.
[0046] While the invention has been described in terms of what are
presently considered to be the most practical and preferred
embodiments, it is to be understood that the invention need not be
limited to the disclosed embodiment. On the contrary, it is
intended to cover various modifications and similar arrangements
included within the spirit and scope of the appended claims, which
are to be accorded with the broadest interpretation so as to
encompass all such modifications and similar structures.
* * * * *