 |
Claims  |
|
|
We claim:
1. A switch assembly for activation by a shaft of a hinge mechanism
operatively connected to a first component, which is rotatable with
respect to a second component, such that an electrical switch of an
electrical circuit is controlled in response to rotatable movement of said
first component and said shaft of said hinge mechanism with respect to
said second component, comprising:
a cam member connected to said shaft of said hinge mechanism for rotation
along with said shaft of said hinge mechanism;
an electrical switch for controlling an electrical circuit;
a lever having a first portion mounted within said switch assembly such
that said lever is movable with respect to said electrical switch, and a
second portion in operable communication with said electrical switch; and
actuating means having a first portion operably connected to said cam
member for rotation along with said cam member and said shaft of said
hinge mechanism, and a second portion for engagement with a third portion
of said lever such that upon rotation of said cam member and said shaft of
said hinge mechanism between a first rotary position of said first
component with respect to said second component and a second rotary
position of said first component with respect to said second component,
said second engagement portion of said actuating means will cause said
lever to move to a first position at which said electrical switch is
closed, and will permit said lever to move to a second position at which
said electrical switch is opened.
2. The switch assembly as defined in claim 1 including means for
accommodating over-rotation of said shaft of said hinge mechanism past a
first fully open position of said hinge mechanism without causing damage
to said switch assembly.
3. The switch assembly as defined in claim 1 including means for providing
a substantially waterproof seal between said switch assembly and said
shaft.
4. A switch assembly for activation by a shaft of a hinge mechanism
operatively connected to a first component, which is rotatable with
respect to a second component, such that an electrical switch of an
electrical circuit is controlled in response to rotatable movement of said
first component and said shaft of said hinge mechanism with respect to
said second component, comprising:
a substantially waterproof housing having an aperture fined within at least
one wall thereof for extension therethrough of said shaft of said hinge
mechanism into said housing;
a cam member connected to said shaft of said hinge mechanism for rotation
along with said shaft of said hinge mechanism;
an electrical switch disposed within said housing for controlling an
electrical circuit;
a lever having a first portion rotatably mounted within said housing such
that said lever is movable with respect to said electrical switch, and a
second portion in operable communication with said electrical switch; and
actuating means having a first portion operably connected to said cam
member for rotation along with said cam member and said shaft of said
hinge mechanism, and a second portion for engagement with a third portion
of said lever such that upon rotation of said cam member and said shaft or
said hinge mechanism between a first rotary position of said first
component with respect to said second component and a second rotary
position of said first component with respect to said second component,
said second engagement portion of said actuating means will cause said
lever to move to a first position at which said electrical switch is
closed, and will permit said lever to move to a second position at which
said electrical switch is opened.
5. The switch assembly as defined in claim 4 including means for
accommodating over-rotation of said shaft of said hinge mechanism past a
first fully open position of said hinge mechanism without causing damage
to said switch assembly.
6. The switch assembly as defined in claim 4 including a substantially
waterproof seal between said housing and said shaft.
7. The switch assembly as defined in claim 4 wherein said housing includes
as least a first case portion, a second cover portion and means for
providing a substantially waterproof seal between said shaft and said
housing.
8. The switch assembly as defined in claim 4 wherein the hinge mechanism is
secured between said first component which comprises a door and said
second component which comprises an appliance and wherein further rotation
of the door between a first fully open position and a second fully closed
position causes said electrical switch to be closed, and rotation of the
door through a predetermined angle between said second fully closed
position and said first fully open position causes said electrical switch
to be opened.
9. The switch assembly as defined in claim 8 wherein said predetermined
angle is between 0-10 degrees.
10. The switch assembly as defined in claim 8 wherein said housing includes
means for securing said housing with respect to said appliance for
cooperation with the shaft of the hinge and for accommodating tolerances
of said switch assembly and said appliance.
11. The switch assembly as set forth in claim 1, wherein:
said first component comprises a door hingedly connected to said second
component which comprises an appliance.
12. The switch assembly as set forth in claim 1, wherein:
said first portion of said actuating means comprises a band member
peripherally surrounding said cam member; and
said second portion of said actuating means comprises an engagement arm
integrally formed with said band member.
13. The switch assembly as set forth in claim 4, wherein:
said first portion of said actuating means comprises a band member
peripherally surrounding said cam member; and
said second portion of said actuating means comprises an engagement arm
integrally formed with said band member.
14. The switch assembly as set forth in claim 1, wherein:
said cam member has a substantially rectangularly configured aperture
defined therein; and
a distal end portion of said shaft of said hinge mechanism has a
substantially rectangular configuration for disposition within said
substantially rectangularly configured aperture defined within said cam
member such that said cam member is rotatably fixed upon and with respect
to said distal end portion of said shaft of said hinge mechanism.
15. The switch assembly as set forth in claim 4, wherein:
said cam member has a substantially rectangularly configured aperture
defined therein; and
a distal end portion of said shaft of said hinge mechanism has a
substantially rectangular configuration for disposition within said
substantially rectangularly configured aperture defined within said cam
member such that said cam member is rotatably fixed upon and with respect
to said distal end portion of said shaft of said hinge mechanism.
16. The switch assembly as set forth in claim 12, wherein:
said band member has a substantially C-shaped configuration.
17. The switch assembly as set forth in claim 13, wherein:
said band member has a substantially C-shaped configuration.
18. The switch assembly as set forth in claim 12, wherein:
said band member is fabricated from a resilient metal strip.
19. The switch assembly as set forth in claim 13, wherein:
said band member is fabricated from a resilient metal strip.
20. The switch assembly as set forth in claim 9, wherein:
said predetermined angle is preferably approximately 4.degree.. |
|
 |
|
 |
Claims |
|
|
|
Description |
|
|
FIELD OF THE INVENTION
The present invention relates generally to switch assemblies, and more
particularly to an electrical switch assembly, for use with an electrical
appliance or the like, which is controlled by a shaft of a hinge
connecting a door or similar member to the appliance and wherein
electrical power to the appliance is cut off upon opening of the door so
as to reduce the risk of injury to a user from the moving parts of the
appliance.
BACKGROUND OF THE INVENTION
Electrical switches and assemblies for appliances such as washers, dryers
or the like are typically provided for cooperation with a door of the
appliance, such as the tub or drum door, to stop the appliance upon
opening of the door. Existing switch assemblies typically are positioned
beneath the top or outer surface of the appliance and are activated by an
engagement arm connected to a distal corner of the door opposite the door
hinge.
The engagement arm extends through an aperture in the top or outer surface
of the appliance so as to make and break contact with the switch. An
example of such a switch is disclosed in U.S. Pat. No. 2,513,804 which is
typically designed to be operated by a very small amount of pressure.
Accordingly, during certain rather dangerous cycles of the appliance, such
as a spin cycle of a washer, the appliance will only operate upon closing
of the door. When the door is opened, the engagement arm on the door
breaks the contact in the switch thereby stopping the appliance.
Such switches, however, are easily defeated by a user merely by inserting
an article or even a finger through the aperture so as to make contact
with the switch and operate the appliance with the door in the open
position. Numerous injuries have resulted when such appliances are
operated with the door in an open position since users tend to put their
hands and arms inside the appliance to clear or balance an item, such as
an article of clothing, during a spin cycle of a washer.
Additionally, due to the remote location of such switches with respect to
the electrical control panel of the appliance, which is typically on the
back of the appliance, additional wiring is required. Such additional
wiring adds significant costs to the appliance both in the price of the
additional wiring itself as well as the associated wiring harnesses,
connectors and the labor required for installing such wiring within the
appliance.
These types of switches are also typically exposed to harsh environments
and extended use, especially when used in an appliance such as a washer or
dryer or the like. Accordingly, these types of switches must be durable
and substantially impervious to environmental conditions including
exposure to high heat, water and harsh liquids such as detergents, bleach,
fabric softeners, spot removers and other similar laundry aids.
It therefore would be desirable to provide an electrical switch assembly
for activation by a door of an appliance to turn the appliance on and off
which cannot be easily defeated by a user, significantly reduces the
amount of wiring and labor involved in its installation and is durable
enough to be utilized under harsh environmental conditions.
SUMMARY OF THE INVENTION
The invention provides a switch assembly, particularly a safety switch
assembly, for activation by the shaft of a hinge of an article, such as an
appliance or the like. The hinge can be utilized to secure a door, such as
the door of a washing machine tub, or other member to the appliance
wherein slight opening and closing of the door causes an electrical switch
within the switch assembly to open and close a desired electrical circuit
of the appliance so as to turn the appliance on and off and reduce the
risk of injury.
The switch assembly is preferably mounted beneath the top surface of the
appliance and cannot be readily accessed by a user in an attempt to defeat
the switch. The switch assembly includes a cam member connected to the
shaft of the hinge for rotation along with the shaft and an actuating band
operably connected to the cam member for rotation along with the cam
member and the hinge.
The actuating band includes an engagement portion for contact with a first
portion of a lever for rotating the lever and causing a second end of the
lever to make and break contact within an electrical switch of the switch
assembly. The switch assembly includes structure for accommodating
over-rotation of the door past the fully open position of the door without
causing damage to the switch assembly or hinge.
The switch assembly is designed for use in environments which expose the
switch assembly to a high degree of heat, moisture and substantially
volatile liquids without causing damage to the switch assembly. Thus, a
novel sealing insert is provided for operable communication between the
cam member and the shaft of the hinge so as to prevent the elements from
entering interior portions of the switch.
The design of the present switch assembly also provides for installation of
the switch in close proximity to the electrical control panel, typically
positioned at the rear of the appliance. Such a design substantially
reduces the cost of materials, such as wiring and associated connectors
and harnesses, as well as the labor involved in installing such materials.
Labor costs can be excessive due to the close confines of the appliance
and the need to protect the wiring against the harsh operating environment
of the appliance.
BRIEF DESCRIPTION OF THE DRAWINGS
Numerous other features and advantages of the present invention will become
readily apparent from the following description of the invention, when
considered in connection with the accompanying drawings in which like
reference characters designate like or corresponding parts throughout the
several views, and wherein:
FIG. 1 is a top plan view, in partial section, of a switch assembly of the
invention illustrated as secured to a shaft of a hinge of a door of an
appliance, the door and appliance being illustrated in dotted outline;
FIG. 2 is a side elevational view of the switch assembly of the invention
secured to a hinge shaft of an appliance door and the frame of the
appliance with the door in the fully open position;
FIG. 3 is a cross-sectional view of a switch assembly of the invention
illustrating the hinge shaft of the appliance door in a fully closed
position;
FIG. 4 is a cross-sectional view of the switch assembly of the invention
illustrating the hinge shaft of the appliance door in a slightly open
position which is sufficient to activate the electrical switch so as to
turn off the appliance;
FIG. 5 is a cross-sectional view of the switch assembly of the invention
illustrating the hinge shaft of the appliance door in a fully open
position;
FIG. 6 is a cross-sectional view of the switch assembly of the invention
illustrating the hinge shaft of the appliance door in an over-rotated
position past the fully open position of FIG. 5;
FIG. 7 is a perspective view of the engagement band and a portion of the
cam member of the switch assembly of the invention illustrating the
typical seating of the cam within an aperture of the engagement band;
FIG. 8 is a perspective view of a portion of the engagement band and the
cam member of the switch assembly of the invention illustrating the
over-rotated position of the cam within the aperture of the engagement
band;
FIG. 9 is a perspective view of an alternate embodiment of the engagement
band of the present invention; and
FIG. 10 is a perspective view of yet another embodiment of the engagement
band of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While this invention is susceptible of embodiment in many different forms,
the specification and the accompanying drawings disclose one or more forms
as examples of the invention. The invention is not intended to be limited
to the embodiments described, the scope of the invention being defined by
in the appended claims.
For ease of description, the device of this invention is described in a
typical operating position and terms such as upper, lower, horizontal, and
the like, are utilized with reference to these positions. It will be
understood, however, that the device of this invention may be
manufactured, stored, transported and sold in an orientation other than
the positions described.
Some of the figures illustrating the embodiments of the device of the
present invention show conventional components, structural details and
mechanical elements that will be recognized by one skilled in the art. The
detailed descriptions of such elements, however, are not necessary to an
understanding of the invention and, accordingly, are not presented herein.
Referring to FIGS. 1 and 2, the switch assembly of the invention is
generally designated with the reference numeral 10. The assembly 10 is
preferably utilized with an electrical appliance or other apparatus
generally designated by the reference numeral 12.
The description of the assembly 10 of the present invention will be
provided as it applies to an appliance 12 in the form of a top loading
electric washing machine or washer. It is to be understood, however, that
the assembly 10 can be utilized with a variety of apparatus without
departing from the teachings of the present invention.
The washer 12 typically includes an outer or top surface or panel 14 having
an opening 16 to its interior which is covered by a door 18 during use.
The door 18 is attached to the top panel 14 by one or more hinges or hinge
elements 20.
In a typical form of the washer 12, the door 18 is either hinged on its
left or rear side as viewed from the front of the washer 12, but can vary.
Additionally, a hinge 20 is provided on each opposite end of the hinged
side of the door 18 rather than a hinge which spans the entire length of
the hinged side of the door 18, such as a "piano" type hinge.
Each hinge 20 includes a hinge shaft or hinge pin 22 having a first
proximal end 24 connected to a mounting insert 18a of the door 18 and a
second distal end 26 having a door prop member 28 connected thereto. As
FIG. 2 illustrates, when the door 18 is in the full-open position, the
door prop member 28 contacts an underside 14a of the top surface 14 of the
appliance 12 so as to initially restrict over-rotation of the door 18 past
the full-open position.
The shaft 22 is preferably circular in cross-sectional configuration except
for a portion of its distal end 26, which is flattened or rectangular in
cross-sectional configuration. The rectangular portion extends through the
switch assembly 10 for engagement therewith as described below.
To protect the switch assembly 10 from the harsh environment typically
encountered within the appliance 12, the switch assembly 10 is preferably
designed to be substantially waterproof. Accordingly, as FIG. 1
illustrates, the switch assembly 10 includes a housing 30 formed of a
first case portion 32 and a second cover portion 34 which are preferably
formed from plastic and are sealed together in a substantially waterproof
manner, such as by ultrasonic welding or "double shear welding."
The second cover portion 34 includes integrally formed flanges 36 for
engagement with the underside 14a of the top surface 14 of the appliance
12. The flanges 36 flex so as to accommodate manufacturing tolerances of
the washer 12 and switch assembly 10. The flexing of the flanges 36 also
provides a spring force to enable retention of the switch assembly 10
between the hinge shaft or pin 22 and the underside 14a of the top surface
14 and further enables the switch assembly 10 to "float" so as to
accommodate any inaccuracies during hinge actuation.
To connect the switch assembly 10 within a desired electrical circuit (not
illustrated), one or more electrical leads 38 extend from the first case
portion 32 and are surrounded by a substantially waterproof cover or boot
40, formed from rubber or the like.
To enable the rectangular portion of the shaft 22 to extend through the
switch assembly 10 for connection with the door prop 28, the housing 30
includes an aperture 42 extending completely therethrough. The aperture 42
preferably extends through both the first case portion 32 and the second
cover portion 34, but can vary. It is to be noted, however, that the
distal end 26 of the shaft 22 can terminate within the housing 30, if
desired, and the door prop 28 can be eliminated thereby only requiring the
aperture 42 to extend through the first case portion 32.
In order to retain the housing 30 in position on the shaft 22 and prevent
the housing 30 from working loose, the second cover portion 34 includes a
retaining ring 44 secured within holding arms 46 formed with the second
cover portion 34. The retaining ring 44 provides the desired positioning
of the housing 30 along the shaft 22 without inhibiting rotation of the
shaft 22 with respect to the housing 30.
A substantially waterproof seal is provided between the shaft 22 and the
housing 30 by means of an insert 47. The insert 47 enables rotation of the
shaft 22 and is sealed against the shaft 22 by a press-fit provided by
means of compression of the first case portion 32 and second cover portion
34 when assembled to form the housing 30. 10 The insert 47 thus seals
against the shaft 22 in both directions, that is, toward the washer 12 and
the door prop 28, to prevent water or other materials from entering the
housing 30. The insert 47 is preferably made of TEFLON, but can vary and
is press-fit between opposing lips 47a and 47b formed with the first case
portion 32 and second cover portion 34, respectively.
As FIG. 3 illustrates, within the interior of the housing 30, the switch
assembly 10 includes a cam member 48, an actuating band 50, a lever 52 and
an electrical switch 54. The cam member 48 preferably has a circular
cross-sectional configuration and is inserted about the rectangular
portion of the shaft 22.
The cam member 48 includes a lug 56, which is tapered on one surface
thereof, for operable cooperation with the actuating band 50 so as to
provide the over-rotation feature as described below. The cam member 48
rotates counterclockwise with the shaft 22 from a first position,
illustrated in FIG. 3, where the door 18 is in its fully closed position
to over-rotated positions of the door 18, as illustrated in FIGS. 5 and 6.
Preferably, the normal full-open position of the door 18 is between 110-120
degrees as FIG. 2 illustrates where the door prop 28 engages the underside
14a of the top surface of the washer 12. As described below, the switch
assembly 10 provides for movement of the door 18 past the normal full-open
position of FIG. 2 to the over-rotated 150 degree position of FIG. 5, or,
in extreme cases, the 180 degree position of FIG. 6 where the door 18
actually contacts the top surface 14 of the washer 12.
The actuating band 50 is substantially in the shape of the letter "C" and
includes an engagement arm 58 and an aperture 60 therethrough. The
engagement arm 58 contacts the lever 52 and the aperture 60 accepts the
lug 56 of the cam member 48.
The actuating band 50 is preferably formed of metal and is somewhat
resilient so as to provide a spring type engagement about the cam member
48. Accordingly, during normal rotation of the shaft 22 and the cam member
48, the actuating band 50 maintains contact and rotates with the cam
member 48.
As FIGS. 7 and 8 illustrate, the aperture 60 of the actuating band 50 is
formed as a slot having a predetermined length and including a first flat
end 62 and a second round end 64. Details of the cooperation between the
aperture 60 and the lug 56 will be provided herein.
As FIG. 3 illustrates, the lever 52 is mounted for rotation within the
first case portion 32 of the housing 30 about a pivot point 66 on one end
thereof and includes a first intermediate portion 68 and a second end 70
opposite the pivot point 66. The first intermediate portion 68 is engaged
by the engagement arm 58 of the actuating band 50 causing rotation of the
lever 52 about the pivot point 66. The 1ever 52 is preferably designed
with a 4:1 ratio with respect to the pivot point 66 and the second
opposite end 70.
The electrical switch 54 is a conventional type of contact switch which is
preferably spring loaded to remain in the open position when at rest as
illustrated in FIGS. 4-6. Upon engagement with the second end 70 of the
lever 52 when the door 18 is in the fully closed position as illustrated
in FIG. 3, the electrical switch 54 is closed.
In operation, as FIG. 3 illustrates, when the door 18 is positioned in the
first fully closed 10 position, the engagement arm 58 of the actuating
band 50 forces the second end 70 of the lever 52 to the right. The second
end 70 thus contacts an actuating member 55 of the electrical switch 54
which maintains contact between fixed contact 72A and movable contact 72B
within the electrical switch 54 so as to enable the appliance 12 to
operate.
Upon a slight opening of the door 18, as illustrated in FIG. 4, which is
preferably approximately four degrees with respect to the horizontal, the
engagement arm 58 of the actuating band 50 rotates slightly clockwise
along with the shaft 22 and the cam member 48 in the direction of arrow
"A". This enables the spring loaded electrical switch 54, including member
55, to rotate the lever 52 about its pivot point 66 and break contact
between fixed and movable contacts 72A and 72B within the electrical
switch 54 so as to stop the flow of electricity to the appliance 12.
Continued opening of the door 18 to the fully opened position illustrated
in FIG. 2, which is approximately 110-120 degrees with respect to the
horizontal, maintains the electrical switch 54 in the open position
thereby preventing operation of the appliance 12. During such rotation in
the direction of arrow "A", the spring engagement of the actuating band 50
enables the actuating band 50 to rotate along with the cam member 48 with
the lug 56 in contact with the first flat end 62 of the aperture 60 of the
actuating band 50.
FIGS. 5 and 6 illustrate the over-rotation feature of the switch assembly
10 where the door 18 is rotated past the full-open 110-120 degree position
to approximately 150 and 180 degrees with respect to the horizontal.
Opening of the lid past 150 degrees is abnormal and is caused by an
extremely large load placed on the door 18, such as by a youngster hanging
on the door 18. If not accounted for, the hinge 20 will suffer permanent
damage.
With the switch assembly 10 of the present invention, however,
over-rotation merely causes the lug 56 of the cam member 48 to rotate
within the aperture 60 of the actuating band 50, which is held in position
by engagement of the engagement arm 58 with a shoulder 74 of the housing
30, from the first flat end 62 to the second round end 64. Thus, the
over-rotation position is accommodated by the switch assembly 10.
Upon closing of the door 18, the cam member 48 rotates with the shaft 22
back to the position illustrated in FIG. 3 such that the engagement arm 58
of the actuating band 50 can engage the lever 52 so as to close the
contacts 72A and 72B of electrical switch 54 and thereby restore
electricity to the appliance 12.
It is to be noted that the length of the aperture 60 and the relationship
with the lug 56 can be adjusted so as to accommodate a variety of
rotational positions of the door 18. Rotation of the door 18 past the 180
degree position can also be accommodated by the switch assembly 10.
For example, as FIG. 5 illustrates, when the door 18 is in the 180 degree
position, the actuating band 50 is held in place by engagement of the
engagement arm 58 and the shoulder 74. Further rotation of the door 18 in
the direction of arrow "A" merely causes the tapered side of the lug 56 to
slide out of the aperture 60 forcing the actuating band 50 away from the
cam member 48. Upon closing of the door 18, the lug 56 reenters the
aperture 60 for cooperation as described above.
Accordingly, the switch assembly 10 cuts off the power to the appliance 12
upon opening of the door 18 and, since it is positioned beneath the top
panel 14 of the appliance 12, cannot be readily accessed by a user to
restart the appliance 12. Additionally, the substantially waterproof
design of the switch assembly 10 enables it to be utilized in the harsh
environments encountered within many appliances, such as washers, dryers
and similar articles.
The switch assembly 10 can be utilized to stop the power to other types of
appliances and apparatus which may not be powered by electricity, but
powered by another source of energy.
FIG. 9 illustrates another embodiment of the actuating band 50a having an
engagement arm 58. Instead of an aperture 60, the actuating band 50a is
formed so as to have a slot 80 defined by opposing edges 82 and 84. The
lug 56 of the cam member 48 is positioned within the slot 80 so that the
actuating band 50a operates substantially the same as the actuating band
50.
FIG. 10 illustrates yet another embodiment of the actuating band 50b having
an engagement arm 58. The actuating band 50b likewise includes a slot 80b
defined by opposing edges 82b and 84b and is positioned substantially
in-line with the engagement arm 58. The actuating band 50b operates
substantially the same as actuating bands 50 and 50a.
Modifications and variations of the present invention are possible in light
of the above teachings. It is therefore to be understood that within the
scope of the appended claims the invention may be practiced otherwise than
as specifically described.
* * * * *
|
|
|
|
|
|
|
Description |
|
