U.S. patent number 3,624,332 [Application Number 05/070,827] was granted by the patent office on 1971-11-30 for snap switch.
This patent grant is currently assigned to Oak Electro/Netics Corp.. Invention is credited to Jan Albert Kilsdonk, Peter Van Benschoten.
United States Patent |
3,624,332 |
Van Benschoten , et
al. |
November 30, 1971 |
SNAP SWITCH
Abstract
An improvement in a two circuit snap switch of a type having
opposed pairs of contacts and a leaflike contact blade positioned
therebetween, which is normally urged into engagement with one pair
of contacts and movable into engagement with an opposed pair of
contacts, wherein an actuator stem extends through the contact
blade and is normally biased against a spring in the interior of
the housing and, wherein another spring stems across the contact
blade and is intersected by the actuator stem. The snap switch of
this invention is characterized by the provision of an offset
medial portion in the actuator through which the contact blade
spring extends, whereby lateral wiping action is imparted to the
contact blade and the contacts it engages during movement thereof
toward, and away from, the opposed contacts.
Inventors: |
Van Benschoten; Peter (Rancho
Santa Fe, CA), Kilsdonk; Jan Albert (Corona, CA) |
Assignee: |
Oak Electro/Netics Corp.
(N/A)
|
Family
ID: |
22097618 |
Appl.
No.: |
05/070,827 |
Filed: |
September 9, 1970 |
Current U.S.
Class: |
200/409; 200/241;
200/243; 200/447; 200/DIG.42 |
Current CPC
Class: |
H01H
13/28 (20130101); H01H 1/18 (20130101); Y10S
200/42 (20130101) |
Current International
Class: |
H01H
13/28 (20060101); H01H 1/12 (20060101); H01H
1/18 (20060101); H01H 13/26 (20060101); H01h
001/36 () |
Field of
Search: |
;200/67,76,67A,67B,164,166BD |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Smith, Jr.; David
Claims
We claim:
1. A snap switch comprising: a housing having an interior; an
opposed pair of contacts positioned in the housing interior; a
switch arm extending across and positioned between said housing
pairs of contacts, said switch arm including a medial opening and a
spring means stressed across said opening between spaced portions
of the switch arm; and an actuator mounted in the housing for
generally reciprocal movement in a direction generally transverse
to said switch arm, said actuator extending through said switch arm
medial opening and having an intermediate portion intersecting said
spring means, and a bottom portion slidably mounted in said
housing, said actuator intermediate portion having surfaces offset
relative to said bottom portion and in engagement with portions of
the switch arm; whereby reciprocal movement of said actuator will
cause movement of said switch arm from a position engaging one of
said pair of contacts to a position engaging the other of said pair
of contacts while simultaneously imparting relatively lateral
movement to said switch arm at the initiation of movement away from
one pair of contacts and during the termination of movement into
engagement with the other pair of contacts.
2. The snap switch of claim 1 wherein the actuator is connected to
biasing means for normally urging the actuator in one direction of
its movement.
3. The snap switch of claim 1 wherein the spring means for the
switch arm is stressed in a state of compression across the switch
arm opening.
4. The snap switch of claim 1 wherein said intermediate portion of
said actuator is canted relative to said bottom portion.
5. The snap switch of claim 1 wherein said intermediate portion of
said actuator is generally upright with said offset surfaces
comprising rib portions thereon.
6. The snap switch of claim 4 wherein said actuator is connected to
biasing means for normally urging said actuator in one direction of
movement and wherein said spring means intersects said actuator on
one side of the switch arm and extends through said canted portion
of said actuator.
7. The snap switch of claim 6 wherein said switch arm has contacts
on opposite ends of each of the faces thereof.
8. The snap switch of claim 1 wherein the actuator bottom portion
is generally perpendicular to the switch arm and the actuator
intermediate portion is canted relative to said bottom portion and
said switch arm and, wherein the spring means intersects the canted
portion of the actuator.
9. The snap switch of claim 1 wherein the actuator intermediate
portion is generally perpendicular to the switch arm and wherein
said offset surfaces includes rib portions on the opposite sides
thereof, said rib portions including upper and lower forwardly
offset portions and an intermediate rearwardly offset portion, and
wherein said switch arm opening includes laterally opposed notches
in which said ribs are received.
10. The snap switch of claim 8 wherein the spring means for said
switch arm is stressed in a state of compression across the switch
arm opening.
11. The snap switch of claim 9 wherein the spring means for said
switch arm is stressed in a state of compression across the switch
arm opening.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to switches and more particularly, to a two
circuit snap switch.
2. Brief Description of the Prior Art
A two circuit snap switch of construction similar to that disclosed
herein is shown in the Roeser U.S. Pat. No. 2,840,657. The
structure shown in the aforementioned Roeser patent includes an
opposed pair of contacts with a two part leaflike contact blade.
Each of the two parts of the blade abut against opposite sides of a
generally centrally positioned actuator which is biased against a
spring. A spring runs through the actuator and is connected under
tension, to each of the two parts of the contact blade. Through
this arrangement the two part contact blade is normally urged into
engagement with one pair of contacts in the housing but is movable
into engagement with the other pair of contacts and upon depression
of the actuator is automatically returnable into engagement with
the one pair of contacts upon release of the actuator.
There is also currently available on the market a two circuit snap
switch, wherein the leaflike contact blade is a one piece structure
and the contact blade spring, which connects two portions thereof,
is under compression and extends through the actuator, to join
opposite sides of the contact blade and provide the desired "flip
action" between the pairs of contacts in the housing. Snap switches
utilizing a contact blade spring under compression are shown in the
patents to Krantz U.S. Pat. No. 1,256,332; Shabeck U.S. Pat. No.
2,661,408; Koenig U.S. Pat. No. 2,918,544; and Barden U.S. Pat. No.
3,196,230.
During operation of snap switches and, other switches as well, dust
and oxidation may cover the contacts and interfere with, or
interrupt, the completion of a circuit through the contacts. Single
circuit snap switches showing structures for "wiping" contacts are
disclosed in the patents to Kryder U.S. Pat. No. 3,030,466 and
Bauer et al. U.S. Pat. No. 3,459,912.
A need and desire has arisen in the art to provide a two circuit
snap switch of the type referred to, wherein the contacts are
automatically wiped or cleaned during operation of the switch. This
invention is directed towards meeting this need and desire.
SUMMARY OF THE INVENTION
This invention is directed, in brief, to the provision of an
improved two circuit snap switch.
The best mode currently contemplated for carrying out the invention
includes the provision of a housing having opposed pairs of
contacts and a one piece leaflike contact blade having contacts
thereon, and positioned between the housing pairs of contacts. The
contact blade is provided with a central opening, and this opening
is intersected by a generally transversely oriented actuator stem.
A coil spring under compression extends across the central opening
in the contact blade and through an opening in the actuator stem.
The actuator stem is also biased against a spring in the bottom of
the housing, thereby normally urging the contact blade stem
upwardly and urging the contact in engagement with the lower of the
two pairs of housing contacts. The intermediate portion of the
actuator which extends through the contact blade and through which
the contact blade compression spring extends, has portions which
are canted relative to the remainder thereof, so that lateral
motion is imparted to the contact blade during reciprocal movement
of the actuator.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the contact blade and actuator stem
utilized in this invention;
FIG. 2 is a section viewed through the snap switch of this
invention showing the switch in its normal position with the
contact blade in engagement with the lower of two pairs of contacts
in the housing;
FIG. 3 is a view similar to FIG. 2 showing the initiation of
movement of the actuator upon initial depression thereof;
FIG. 4 is a view similar to FIGS. 3 and 2 showing the actuator
fully depressed and the contact blade moved into engagement with
the upper of the two pairs of contacts in the housing, and;
FIG. 5 is a fragmentary enlarged perspective view of a modified
form of the actuator element for use in carrying out the principle
of this invention.
While this invention is susceptible of embodiment in many different
forms, there is shown in the drawings and will herein be described
in detail a specific embodiment therefor, with the understanding
that the present disclosure is to be considered as an
exemplification of the principles of the invention and is not
intended to limit the invention to the embodiment illustrated.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT
The switch 10 of this invention includes a generally boxlike
housing 12 having a substantially hollow interior 12a. An upper
pair of contacts 14 and 16 are located in the upper portion of the
housing and are mounted on inwardly turned ends 18a and 20a of
terminal arms 18 and 20. Terminal arms 18 and 20 reside in slots 22
and 24, which open to the exterior of the housing. Arms 18 and 20
terminate in terminal lugs 18b and 20b which are positioned to the
exterior of the housing.
A lower pair of contacts 26 and 28 are located in the lower portion
of the housing and are in general vertical alignment with the upper
pair of contacts 14 and 16. Lower contacts 26 and 28 are connected
to the inturned ends 30a and 32a of arms 30 and 32. Terminal arms
30 and 32 reside in slots 34 and 36 which open to the exterior of
the housing. Arms 30 and 32 terminate in terminal lugs 30b and 32b,
also located to the exterior of the housing.
A switch button 40 is provided for actuating the switch. Switch
button 40 extends through a medially positioned opening 42 in the
top of housing 12 and the underside of button 40 is provided with
an enlarged flange 44 to retain the button 40 associated with the
housing 12. An actuator member, plunger, or stem 46 is connected to
the switch button 40 and is positioned generally uprightly in the
central portion of the housing 10. The actuator 46 includes an
upper tab 48 which is inserted into button 40 to connect the
actuator 46 thereto. A canted medial portion or offset portion 50
extends from the upper tab portion 48 to a lower upright bottom
portion 52 having a slot 54 which opens to the bottom thereof. The
bottom portion 52 of actuator 46 is positioned within medial recess
56 in the lower portion of the interior of the housing, and tracks
in upright slots 56a at the opposite sides of the recess 56. Recess
56 also receives a coil spring 58 for normally biasing the actuator
upwardly or in a direction towards the upper pair of contacts.
The switch 10 further includes a unitary leaflike contact blade 60
of suitable spring metal, preferably brass. Contact blade 60 is
disposed between the upper and lower pair of contacts and is
generally coextensive in length with the distance across contacts
14 and 16 and contacts 26 and 28. The contact blade 60 includes an
upper face 60a and a lower face 60b and generally centrally located
opening 62. Opening 62 has laterally opposed notches, such as 62a,
through which the actuator 46 extends, and, particularly, the
medial canted portion 50 thereof.
Opposite ends of the central opening 62 of contact blade 60 are
provided with inwardly directed ears 64 and 66. A coil spring 68 is
connected to, and extends between, ears 64 and 66 under
compression. In its normal orientation, spring 68 is slightly bowed
outwardly relative to the blade 60 as seen in FIGS. 1, 2 and 4. The
spring 68 extends through an opening 50a in the canted portion 50
of the actuator 46. Contact blade 60 further includes an upper pair
of contacts 70 and 72 on the upper face 60a for engagement with
housing upper contacts 14 and 16, and a lower pair of contacts 74
and 76 on the lower face 60b for engagement with the housing lower
contacts 26 and 28.
The normal position of the switch is indicated in FIG. 2. Spring 58
biases actuator 46 upwardly to force spring 68 to its upwardly
bowed position which, in turn, works in opposition against contact
blade 60 to force the blade downwardly relative to the housing and
into engagement with lower contacts 26 and 28. When button 40 is
depressed to initiate movement of the contact blade upwardly, the
canted medial portion 50 of actuator 46, tracking in opposed
notches 62a, imparts slight lateral movement to blade 60, as shown
in FIG. 3. Continued depression of button 40 reverses the
orientation of spring 68, forcing blade 60 upwardly into engagement
with upper contacts 14 and 16. At the termination of this upward
movement, actuator 50 is still not completely depressed so that
further depression thereof imparts more lateral motion to blade 60.
When button 40 is released, spring 58 forces spring 68 upwardly to
return blade 60 downwardly to the position shown in FIG. 2. During
this return movement, slight lateral movement is imparted to the
blade 60 at the initiation of its departure from the upper contacts
and at the termination of its movement into engagement with the
lower contacts.
A modified form of the actuator element of this invention is shown
in FIG. 5. There the button 40 is connected to actuator 146
preferably in the same fashion as described with respect to
actuator 46 and preferably actuator 146 would also have a tab means
(not shown) for making this connection. Actuator 146 has a
generally upright medial portion 150 in contrast to the canted
medial portion 50 of actuator 46. Actuator 146 has a through
opening 150a for receiving spring 68 in the same fashion as
actuator 46. The lower end 152 of actuator 146 is also generally
uprightly aligned with the remainder of the actuator and is
provided with slots 154a and 154b in the bottom thereof for
receiving a biasing spring such as spring 58.
The medial portion 150 of actuator 146 includes portions which are
offset relative to the remainder of the actuator. These offset
portions are shown as laterally outwardly extending ribs 156 on the
opposite sides of medial portion 150. It is intended that the ribs
156 would be received in notches 62a of contact blade 60. Ribs 156
include a first or upper forwardly oriented portion 158, a second
or medial rearwardly oriented portion 160 and, a third or lower
forwardly oriented portion 162. This rib configuration causes
relative lateral wiping movement of the contact blade 60 in two
directions during reciprocal movement of actuator 146 responsive to
depression of button 40.
Thus, it can be seen that with the switch of this invention, a
relative lateral wiping action occurs between the blade contacts
and the housing contacts automatically as an incident to the
movement of the contact blade between the upper and lower portions.
This insures that the contacts will be maintained relatively free
of dust particles and minor particles of oxidized matter, and thus
insures a good circuit through the contacts.
The foregoing detailed description has been given for clearness of
understanding only, and no unnecessary limitations should be
understood therefrom, as some modifications may be obvious to those
skilled in the art.
* * * * *