MAGNETIC COMPASS

COMPAS MAGNETIQUE

English Abstract

A magnetic compass includes a base having a receiving chamber for receiving a compass body, a battery chamber for receiving a battery set, an illuminant chamber for receiving an illuminant, and a locating chamber for receiving an electrically conductive member. The illuminant has a first terminal suspended above the battery set. A push button is supported on the first terminal of the illuminant for pressing by the user to force the first terminal of the illuminant downwards into contact with a first terminal of the battery set. The conductive member has a base frame mounted in the locating chamber, and a contact portion extended from the base frame and inserted into the battery chamber and pressed on a second terminal of the battery set. A second terminal of the illuminant is electrically connected to the base frame of the conductive member.

French Abstract

Boussole magnétique comprenant une base constituée d'un compartiment pour un corps de boussole, un compartiment pour un ensemble de piles, un compartiment pour une source lumineuse et un compartiment pour un élément de conduction électrique. La source lumineuse comporte une première borne suspendue au-dessus de l'ensemble de piles. Un bouton-poussoir repose sur la première borne de la source lumineuse; l'utilisateur appuie sur le bouton pour pousser la première borne de la source lumineuse vers le bas afin qu'elle entre en contact avec une première borne de l'ensemble de piles. L'élément conducteur contient une structure de base montée dans le compartiment du dispositif de boussole. Une partie de contact fait saillie à partir de la structure de base et entre dans le compartiment des piles. L'utilisateur l'appuie sur une deuxième borne de l'ensemble de piles. Une deuxième borne de la source lumineuse est reliée par un circuit électrique à la structure de base de l'élément conducteur.

Claims

WHAT IS CLAIMED IS:
1. A magnetic compass comprising:
a base having a hollow base body and a top cover covering said hollow base
body, said hollow base body having a receiving chamber, a top opening in a top
side of
said receiving chamber, a battery chamber, a battery insertion opening in a
top side of
said battery chamber, and an illuminant chamber in communication between said
receiving chamber and said battery chamber, said top cover closing said top
opening of
said hollow base body, said top cover having a view window corresponding to
said
receiving chamber and a through hole corresponding to said battery chamber;
a compass body situated within said receiving chamber of said hollow base
body of said base, said compass body having a housing, a magnetic needle
pivotally
mounted within said housing, and an indication card mounted in said housing;
a battery set mounted within said battery chamber, said battery set having a
first terminal thereof aimed at said battery insertion opening and a second
terminal;
an illuminant situated within said illuminant chamber and aimed at a
periphery of said compass body, said illuminant having a first terminal
suspended in
said battery insertion opening and a second terminal;
a push button supported on the first terminal of said illuminant above said
battery chamber and partially inserted through the through hole of said top
cover to the
outside of said base for pressing by a user to force the first terminal of
said
illuminant downwards into contact with the first terminal of said battery set;
and
a top lid pivotally connected with one end thereof to said base by a pivot for
covering said base, said top lid having a biconvex lens mounted therein;
wherein said hollow base body further comprises a locating chamber
disposed at one side of and in communication with said battery chamber; said
magnetic
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compass further comprises an electrically conductive member for connecting one
terminal of said battery set to the second terminal of said illuminant, said
conductive
member having a base frame mounted in said locating chamber, and a contact
portion
extended from said base frame and inserted into said battery chamber and
pressed on
the second terminal of said battery set; the second terminal of said
illuminant is
electrically connected to said base frame of said conductive member.
2. The magnetic compass as claimed in claim 1, wherein said conductive
member further comprises two protruding strips respectively upwardly extended
from
two opposite lateral sides of said base frame and respectively stopped against
one side
of said locating chamber at one side to force said base frame against an
opposite side
of said locating chamber.
3. The magnetic compass as claimed in claim 1, wherein said conductive
member further comprises a locating strip outwardly extended from a top side
of
said base frame and curved backwards to hold down the second terminal of said
illuminant on said base frame.
4. The magnetic compass as claimed in claim 1, wherein said contact portion
of said conductive member is upwardly outwardly extended from a bottom of said
base
frame and smoothly arched.
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Description

CA 02470749 2004-06-10
MAGNETIC COMPASS
BACKGROUND OF THE INVENTION
1, Field of the Invention
The present invention relates to a magnetic compass and more particularly, to
such a magnetic compass that is usable in the dark.
2. Description of the Related Art
FIG. 6 is an exploded view of a magnetic compass 80 constructed according
to US Patent No. 6,578,277. According to this design, the magnetic compass 80
comprises a compass body 81, an illuminant 82, a conductive copper ring 83, a
battery
set 84 (which is consisted of a plurality of flat cylindrical lithium
batteries that are
stacked o»e by one), a base 85, a top lid 86, and a push button 87. The base
85
comprises a receiving chamber 851 that accommodates the compass body 81, a
battery
chamber 852 that accommodates the conductive copper ring 83, and an illuminant
chamber 853 that accommodates the illuminant 82. The battery set 84 is
situated within
the conductive copper ring 83. The illuminant 82 comprises a first terminal
821
suspending above the battery set 84 and a second terminal 822 electrically
connected
to the conductive copper ring 83. The top lid 86 is covered on the base 85,
having a
button hole 861 corresponding to the battery chamber 852. The push button 87
is
mounted in the button hole 861 of the top lid 86 and supported on the first
terminal 821
of the illuminant 82. When pressed the push button 87, the first terminal 821
of the
illuminant 82 is forced into contact with the battery set 84, thereby closing
the circuit
of the battery set 84 and the illurninant 82, and therefore the illuminant 82
is turned on
to emit light toward the periphery of the compass body 81. Therefore, the
magnetic
compass 80 is effectively usable under low light conditions.
Refernng to FIG. 7 and FIG. 6 again, the inner diameter of the conductive
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copper ring 83 is greater than the outer diameter of the battery set 84 so
that the battery
set 84 can conveniently be put into or taken out of the battery chamber 852.
However,
the presence of a gap between the conductive copper ring 83 and the battery
set 84 may
cause contact failure, thereby resulting in unstable supply of electricity to
the
illuminant 82.
SUMMARY OF THE INVENTION
The present invention has been accomplished under the circumstances in
view. It is the main object of the present invention to provide a magnetic
compass that
provides a stable illumination effect.
To achieve this object of the present invention, the magnetic compass
comprises a base, a compass body, a battery set, an illuminant, a push button
and an
electrically conductive member. The base includes a hollow base body and a top
cover
covering the hollow base body. The hollow base body has a receiving chamber
for
receiving the compass body, a battery chamber for receiving the battery set,
an
illuminant chamber for receiving the illuminant, and a locating chamber for
receiving
the conductive member. The top cover has a through hole corresponding to the
battery
chamber. The illuminant has a first terminal suspended above the battery set.
The push
button is supported on the first terminal of the illuminant and movably
mounted in the
through hole of the top cover for pressing by the user to force the first
terminal of the
illuminant downwards into contact with a first terminal of the battery set.
The
conductive member has a base frame mounted in the locating chamber, and a
contact
portion extended from the base frame and inserted into the battery chamber and
pressed on a second terminal of the battery set. A second terminal of the
illuminant is
electrically connected to the base frame of the conductive member.
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BRIEF DESCRIPTION OF TIIE DRAWINGS
FIG. 1 is an exploded view of a magnetic compass according to the present
invention.
FIG. 2 is an enlarged view of a part of FIG. 1.
FIG. 3 is a top view in an enlarged scale of a part of the bas of the magnetic
compass according to the present invention.
FIG. 4 is a top view in an enlarged scale of the magnetic compass according
to the present invention.
FIG. 5 is a sectional view taken along line 5-5 of FIG. 4.
FIG. 6 is an exploded view of a magnetic corr~pass constructed according to
US Patent No. 6,578,277.
FIG. 7 is a sectional view in an enlarged scale of a part of the magnetic
compass shown in FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
Refernng to FIG. l, a magnetic compass 1 is shown comprised of a base 10,
a compass body 20, a battery set 30, an illuminant 40, a push button S0, an
electrically
conductive member 60, and a top lid 70. The base 10 comprises a hollow base
body 11
and a top cover 12 covering the hollow base body 11.
Refernng to FIGS. 2 and 3 and FIG. 1 again, the hollow base body 11
comprises a bottom wall 111, an upright peripheral wall 112 perpendicularly
extended
around the border of the bottom wall lll, a barrel A13 perpendicularly
upwardly
extended from the bottom wall 111 and peripherally partially formed integral
with the
upright peripheral wall 112, a receiving chamber 114 surrounded by the upright
peripheral wall 112 outside the barrel 113, a top opening 115 in the top side
of the
receiving chamber 114, a battery chamber 116 surrounded by the barrel 113, a
battery
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insertion opening 117 in the top side of the hattery chamber 116, an
illuminant
chamber 118 formed integral with the periphery of the barrel 113 in
communication
between the receiving chamber 114 and the battery chamber 116, and a locating
chamber 119 formed integral with the periphery of the barrel 113 in
communication
with the battery chamber 116. 'The top cover 12 is fastened to the hollow base
body 11
with screws 121 to close the top opening 115 of the hollow base body 11,
having a
view window 122 corresponding to the receiving chamber 114 and a through hole
123
corresponding to the battery chamber 116 (see FIG. 1).
The compass body 20 is situated within the receiving chamber 114 of the
hollow base body 11 of the base 10, comprising a housing 21, a magnetic needle
22
pivotally mounted within the housing 21, an indication card 23 adhered to the
top
surface of the bottom wall of the housing 21, and an ornamental ring 24
fastened to the
top side of the housing 21.
The battery set 30 is comprised of two flat cylindrical lithium batteries,
which are arranged in a stack (electrically connected in series), and mounted
within the
battery chamber 115 with one terminal, for example, the positive terminal
aimed at the
battery insertion opening 117.
Referring to FIGS. 4 and 5, the illuminant 40 according to the present
preferred embodiment is an LED (light emitting diode) situated within the
illuminant
chamber 118 and aimed at the periphery of the compass body 20, having a first
terminal 41 suspended in the battery insertion opening 117 and a second
terminal 42
suspended in the top side of the locating chamber 119.
The push button 50 is supported on the first terminal 41 of the illuminant 40
above the battery chamber 116 and partially inserted through the through hole
123 of
the top cover 12 to the outside of the base 10 for pressing by the user to
force the first
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terminal 41 of the illuminant 40 downwards into contact with the positive
terminal of
the battery set 30.
Referring to FIG. 5 again, the electrically conductive member 60 made of
metal comprises a flat rectangular base frame 61 mounted in the locating
chamber 119,
a contact portion 62 extended from the bottom side of the flat rectangular
base frame
61 and curved upwardly outwards toward the inside of the battery chamber 116
and
pressed on the other terminal, namely, the negative terminal of the battery
set 30, two
protruding strips 64 respectively upwardly extended from two opposite lateral
sides of
the flat rectangular base frame 61 on the middle and respectively stopped
against the
inside wall of the locating chamber 119 at one side to :force the flat
rectangular base
frame 61 against the inside wall of the locating chamber 119 at the other
side, and a
locating strip 65 outwardly extended from the top side of the flat rectangular
base
frame 61 and curved backwards to hold down the second terminal 42 of the
illuminant
40 on the flat rectangular base frame 61. Therefore, the illuminant 40 and the
metal
conductive member 60 are electrically connected.
Refernng to FIG. 1 again, the top lid 70 is pivotally connected with one end
thereof to the base 10 by a pivot 71, and adapted to close the top open side
of the base
10 and to further protect the compass body 20 against external bodies. The
user may
open the top lid 70 from the base 10 to read the indication of the magnetic
needle 22 of
the compass body 20 through the view window i22 of the top cover 12 of the
base 10.
Further, a biconvex lens 72 is mounted in the top lid 70.
As indicated above, the metal conductive member 60 holds down the battery
set 30 in the battery chamber 116, therefore fhe battery set 30 is constantly
maintained
in positive contact with the metal conductive member 60. When the user pressed
the
push button 50 to force the first terminal 41 of the illuminant 40 into
contact with the
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positive terminal of the battery set 30, electricity is provided to the
illuminant 40,
thereby causing the illuminant 40 to emit light toward the periphery of the
compass
body 20.
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Representative Drawing