U.S. patent number 3,773,998 [Application Number 05/297,636] was granted by the patent office on 1973-11-20 for pedestal and spring member for key actuator of diaphragm switch.
This patent grant is currently assigned to Chomerics, Inc.. Invention is credited to John G. Coulter, Richard E. Seeger, Jr..
United States Patent |
3,773,998 |
Seeger, Jr. , et
al. |
November 20, 1973 |
PEDESTAL AND SPRING MEMBER FOR KEY ACTUATOR OF DIAPHRAGM SWITCH
Abstract
A keyboard actuator which includes a first member adapted to be
supported over a circuit board having a conductive pattern thereon
and supporting a resilient conductive layer by way of an insulator
layer having a window therethrough in line with at least a portion
of the conductive pattern, a second member snapable into the first
member and slidable while held therein, first and second resilient
biasing means, the first biasing means separating the members and
the second biasing means extending between the second member and
the conductive layer.
Inventors: |
Seeger, Jr.; Richard E.
(Topsfield, MA), Coulter; John G. (Reading, MA) |
Assignee: |
Chomerics, Inc. (Woburn,
MA)
|
Family
ID: |
23147131 |
Appl.
No.: |
05/297,636 |
Filed: |
October 16, 1972 |
Current U.S.
Class: |
200/517;
200/330 |
Current CPC
Class: |
H01H
13/705 (20130101); H01H 13/14 (20130101); H01H
2229/034 (20130101); H01H 2233/056 (20130101); H01H
2233/024 (20130101); H01H 2209/078 (20130101); H01H
2235/004 (20130101) |
Current International
Class: |
H01H
13/70 (20060101); H01H 13/705 (20060101); H01H
13/14 (20060101); H01h 013/06 (); H01h
013/52 () |
Field of
Search: |
;200/159B,159R,159A,153V,172R,172A |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Smith, Jr.; David
Assistant Examiner: Vanderhye; Robert A.
Claims
We claim
1. In a keyboard or the like which includes an insulator board
having electrical contact means thereon, insulator means having a
window therethrough in alignment with at least a portion of the
contact means and a resilient electrically conductive sheet means
positioned on the insulator layer which has the property of being
deformable by a force applied thereto to make electrical contact
with the contact means by extending through the insulator means
window and then springing back to a position out of electrical
contact with the contact means, the improvement comprising a base
member positioned over the conductive layer and having a portion of
a movable member slidably positioned therein, first resilient
biasing means positioned between the base member and the movable
member to urge the movable member and the base member apart, a lip
forming a part of the base member to maintain at least a portion of
the movable member within the confines of the base member by
entrapping projections attached to the movable member, a second
resilient biasing means positioned in contact with the movable
member and positioned to apply a force to the conductive sheet
means to deform it in order to make electrical contact with the
contact means, said base member having guide slots along the inner
wall thereof in which the projections are slidably movable, in
which the base member includes a pedestal and in which the movable
member includes a first bore, the first bore of the movable member
positioned about at least a portion of the pedestal.
2. In a keyboard as claimed in claim 1 in which the pedestal has a
bore in which the second resilient biasing is positioned, said
second resilient biasing means extending into the bore beyond the
pedestal to engage the movable member.
3. In a keyboard as claimed in claim 2 in which the spring is of
the type which will compress once bottoming the conductive layer
against the contact means.
4. In a keyboard according to claim 3 in which the first resilient
biasing means surrounds the pedestal.
5. In a keyboard according to claim 4 in which the second resilient
biasing means rests directly on the conductive layer.
6. In a keyboard according to claim 5 in which the resilient
biasing means are coil springs.
7. In a keyboard according to claim 6 in which the base member
includes rods which extend through holes in the board, the
conductive layer and the insulator layer to form a sandwich.
Description
STATEMENT OF THE DISCLOSURE
This invention is directed to a new and improved keyboard actuator
particularly adapted for use with a keyboard of the type utilizing
a resilient conductive layer to make electrical contact with an
electrical conductive contact.
In particular, the present invention is directed to a new and
improved keyboard construction in which two parts, one movable and
the other fixed in place are snaped together and two resilient
biasing means are provided one of which is used to bias the movable
part away from the fixed in place part and the other resilient
biasing means is positioned between the movable part and the
conductive layer in order to apply a force thereto to cause the
conductive layer to contact the contact when a force is applied to
the movable part.
The present invention is usable in place of the switch actuating
means disclosed in copending U.S. Pat. applications Ser. No.
145,212 filed May 20, 1971 by Richard E. Seeger, Jr. and George T.
Hodgson, Jr. and Ser. No. 154,752 filed June 12, 1971 by Richard E.
Seeger, Jr. and William J. Lynn. The entire disclosure of these
patent applications are incorporated herein by reference
hereto.
The present invention permits a keyboard to be constructed with a
minimum of parts, with a reduction in fabrication and assembly
costs. The major parts (those not resilient in nature) used herein
may be constructed of plastic moldable in a conventional manner
thus providing significant cost savings.
BRIEF DESCRIPTION OF THE DISCLOSURE
The keyboard actuator of the disclosure includes a fixed in place
member for mounting on a circuit board over a resilient conductive
layer, the fixed in place member having means for retaining a
movable member snapable therein and adapted for slidable movement
therein and first and second resilient biasing or spring means, the
first spring means separating the members and the other positioned
to be forced against the conductive layer upon movement of the
movable member towards the conductive layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view with the parts removed of a keyboard utilizing
the actuator of the invention;
FIG. 2 is a sectional view taken along line 2--2 in FIG. 1
illustrating the key in position when at rest;
FIG. 3 is a sectional view similar to FIG. 2 illustrating the
actuator when a force is applied thereto;
FIG. 4 is a sectional view taken along line 4--4 in FIG. 2; and
FIG. 5 is a sectional view taken along line 5--5 in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference should now be had to FIGS. 1-5 for a description of the
preferred embodiment of the disclosure. At 6 there is shown a
keyboard which comprises an outer decorative frame 7 in which there
is mounted the working parts of the invention. The frame may be
mounted to the working parts as shown in the aforementioned U.S.
Pat. application Ser. No. 145,122 or any other conventional manner.
The operating parts of the invention include an insulator board 8
(e.g., Bakelite, Formica) of the conventional type used in printed
circuit applications and having holes 8a formed therethrough.
At 9 there is provided an electrical contact means or electrical
pathway which may be formed on the board using conventional printed
circuit etching techniques i.e., where copper sheet is etched away
or may be formed using conventional screening techniques where an
electrically conductive coating is laid down.
Various circuit patterns are shown in the aforementioned patent
applications which are incorporated herein by reference hereto.
At 10 there is shown an insulator layer for example, of plastic
such as sold under the trademark Mylar and having a window 10a
extending therethrough in line with at least a portion of the
electrical contact means and mounting holes 10b. Positioned on the
layer 10 is a resilient conductive layer or sheet 11 having
mounting holes 11a. The layer 11 is selected of a material which
may be forced through the window 10a into contact with the contact
means 9 (see FIG. 3) and then springs back to its at rest position
shown in FIG. 2 when a force applied thereto is removed.
Various materials may be used as the conductive layer as set forth
in the aforementioned referred to applications with the preferred
material being a conductive plastic formed of silicone rubber
(rubber is defined as a plastic in the context used herein) filled
with silver flakes e.g., between 10 to 80 percent by volume.
At 12 in the drawing there is shown the actuator of the invention
which includes a fixed in place or base member 13 having a hollow
cavity 13a with a lip 13aa formed along the top thereof. The cavity
13a is provided with two guide channels or slots 13b within the
sidewall thereof and has a pedestal 13c extending upwardly
therefrom. The pedestal is provided with a bore 13d as shown.
A movable or key member is shown at 14 on which indicia e.g.,
numbers or letters may be mounted thereon as shown in FIG. 1.
The movable member 14 is positioned for slidable up and down
movement with respect to the member 13 and has a portion thereof
positioned within the confines of the cavity 13a. The member 14 is
provided with projections 14a which are positionable in the slots
13b for travel therein.
The projections 14a as well as the member 14 forming a part thereof
are preferably formed of a plastic material which is sufficiently
flexible and resilient e.g., polypropylene, polyethelene, etc., so
that it may snap past the lip 13aa into the cavity 13a and the
slots 13b. Alternatively the base member or both members may be
selected of a resilient type of material to allow the members to
snap together.
The member 14 is also provided with first and second bores 14b and
14c. The bore 14c is constructed so that it is positionable over
the pedestal 13c and is slidably guided thereby.
In order to urge the key member upwardly as shown in FIG. 2 there
is provided a resilient biasing means such as a spring 16. The
spring 16 is positioned about the pedestal 13c and at one end is
located in the bore 14b.
A second resilient biasing means such as a spring is shown at 16
and performs the function of urging the conductive layer 11 against
the contact means 9 upon application of a force to member 14 (see
FIG. 3). Each of the springs may be coil springs as shown.
The spring 16 is selected such that when it is in the position
shown in FIG. 2 it applies little or no force to the layer 11 and
when it is forced downwardly by the member 14 it remains virtually
uncompressed (see FIG. 3) and distorts the layer 11 so that it
engages the contact means 9. The spring 16 is also preferably
selected such that when the layer 11 bottoms against the contact
means 9, it then slightly compresses so as not to substantially
injure the layer 14 surface by penetrating into it. A protective
cover layer e.g., of plastic may be positioned between the spring
16 and the layer 11 to provide further protection.
The actuator 12 is preferably mounted to the board 8 by the
provision of rods 13e extending from the member 13. The rods extend
through the holes 8a, 10b, and 11a to join them together in a
sandwich.
The rods are preferably constructed of a plastic material e.g.,
polypropylene, nylon which may be softened with heat to form the
heads 13f. Alternatively the rods may be threaded and nuts may then
be used to hold the sandwich together.
As shown in the aforementioned patent application or disclosed in
the aforementioned patent applications, the contact means may be
segmented and thus the layer 11 may be used to close a circuit
between the segments or alternatively the layer 11 may be grounded
and the contact means made high (+) so as to complete a circuit.
Connector pins as shown in the aforementioned patent applications
may be used to make contact with the layer 11 and the contact means
9.
* * * * *