U.S. patent number 3,592,983 [Application Number 05/030,876] was granted by the patent office on 1971-07-13 for improved detent means for slide switch and printed circuit structure.
This patent grant is currently assigned to International Standard Electric Corporation. Invention is credited to Rolf J. Falkner, Heinz E. J. Kroll.
United States Patent |
3,592,983 |
Kroll , et al. |
July 13, 1971 |
IMPROVED DETENT MEANS FOR SLIDE SWITCH AND PRINTED CIRCUIT
STRUCTURE
Abstract
A slide switch of low profile particularly adapted for use with
printed circuits. The terminals of the switch are stationary
conductor pattern elements of the printed circuit and the movable
contact parts are carried by a slider of insulating material. The
slider is mounted in a circuit board slot which serves as a track
for axial slider action. A caliper type mechanism (resilient detent
arm) engages detent slots in the circuit board or provides the
coupling means for ganging multiple switch stages to each
other.
Inventors: |
Kroll; Heinz E. J.
(Heroldsberg, DT), Falkner; Rolf J. (Nurnberg,
DT) |
Assignee: |
International Standard Electric
Corporation (New York, NY)
|
Family
ID: |
5732148 |
Appl.
No.: |
05/030,876 |
Filed: |
April 22, 1970 |
Foreign Application Priority Data
|
|
|
|
|
Apr 24, 1969 [DT] |
|
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P 19 20 784.2 |
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Current U.S.
Class: |
200/16D; 200/16R;
200/292; 200/295 |
Current CPC
Class: |
H01H
1/403 (20130101); H01H 15/005 (20130101) |
Current International
Class: |
H01H
15/00 (20060101); H01H 1/12 (20060101); H01H
1/40 (20060101); H01h 015/00 () |
Field of
Search: |
;200/11,14,16,16R,166PC,166SD,168S |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Scott; J. R.
Claims
What we claim is:
1. A slide switch in which the stationary contacts are parts of the
printed conductors of a printed circuit board and the movable
contact parts are carried by a slide member of insulating material
comprising the combination of:
means defining a mounting slot through the thickness of said
circuit board, said slot being elongated in the direction of
actuation of said slide switch;
slide mounting means for holding said slide in place with
substantially only translational freedom in the direction of said
actuation and with said movable contact parts in position to
contact said stationary contacts, at least some parts associated
with said slide protruding from the side of the board opposite said
stationary contacts;
a plurality of detent slots substantially along the actuation
centerline of said mounting slot and spaced relationship at one end
of said mounting slot;
and detent means including at least one resilient detent arm having
a nose engageable in one of said detent slots and being attached to
said slide, said detent arm extending toward said detent slots and
being adapted to exert lateral contact pressure on said board
thereby to facilitate engagement of said nose into one of said
detent slots in response to actuation of said switch to effect a
corresponding switch position.
2. Apparatus according to claim 1 in which said detent means is
defined as a substantially identical caliperlike pair of said
resilient arms extending from said slide toward said detent slots
on opposite surfaces of said circuit board, whereby the
corresponding noses of said resilient arms engage the same one of
said detent slots from opposite sides of said circuit board to
position said switch to a corresponding switch position.
3. The invention set forth in claim 2 in which said slide includes
a head member having an undercut extending oppositely from the
direction of extension of said resilient arms, whereby the
resilient arms of a second one of said slides may be ganged thereto
by sliding the resilient arms of said second slide over said head
member until the noses of said resilient arms engage said
undercut.
4. Apparatus according to claim 3 in which the lateral dimension of
said head member and the depth of said undercut are such that said
resilient arms mated thereto are spread laterally against their
resiliency more than said resilient arms are spread when
functioning as a detent mechanism, whereby the separation force is
greater than the force required to actuate said switch from a
detented position.
5. A slide switch in which the stationary contacts are parts of the
printed conductors of a printed circuit board and the movable
contact parts are carried by a slide member of insulating material,
comprising the combination of:
means defining a mounting slot through the thickness of said
circuit board, said slot being elongated in the direction of
actuation of said slide switch;
and resilient means extending from said slide member through said
slot, said resilient means being located and shaped to resiliently
grip the edges of said mounting slot thereby to maintain contact
pressure of said movable contact parts against the surface of said
circuit board and said stationary contacts, and also to restrict
said slide member from substantial movement except in the said
direction of actuation.
6. Apparatus according to claim 5 in which said resilient means
extending through said slot comprise a plurality of resilient
tongues extending substantially normal to said circuit board
through said mounting slot, and means are included at the extreme
end of each of said tongues for engaging the edges of said mounting
slot to provide said contact pressure of said movable contact parts
against the surface of said circuit board.
7. Apparatus according to claim 6 in which said tongues are four in
number, two on each side of said slide in spaced relationship, and
said means for engaging the edges of said mounting slot consists of
a barblike nose at said extreme end of each of said tongues.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This application if filed with claim of priority pursuant to 35
U.S.C. 119, the same invention having been filed by applicant in
the Federal Republic of Germany as application No. P 1920784.2, on
Apr. 24, 1969.
BACKGROUND OF THE INVENTION
1. Field of The Invention
The present invention relates to switches and more particularly to
slider type switches adapted for use on printed circuit boards in
electronic equipment.
2. Description of The Prior Art
In general, there have been a number of approaches to the problem
of constructing a slide switch to be mounted into a printed
circuit, in which the stationary contact parts are components of,
or held by said printed circuit and the movable contact parts are
carried by a slider of insulating material. Such slide switches are
particularly useful in the construction of broadcast receivers,
tape recorders and dictating machines. In such devices of current
manufacture, printed circuits are widely used. A specific example
is the wave switch of a broadcast received. In known slide
switches, the stationary contact parts are formed as elements of
the conducting pattern of the printed circuit. That particular
prior art is typically shown in German Petty Pat. No. 1 745
285.
In other known slide switches, the stationary contact parts are
installed in the printed circuit board, in the form of round pins
which are pressed or driven into the printed circuit for example,
this art being described in German Pat. No. 1 121 163. In other
known switch structures, resilient contact bridges serve as movable
contacts, the bridges being guided along the printed circuit board.
An important disadvantage of these known switches is that they
occupy relatively large spaces. Accordingly, their use is difficult
where minimum space is available.
A flat design requiring little space is obtained if contact springs
attached to the printed circuit board and connected with the
conducting pattern serve as movable contact parts. In that switch
form, the contact springs are actuated by a slider of insulating
material which is guided in a recess of the printed circuit board
as described in German Petty Pat. No. 1,840,481. That configuration
suffers the disadvantage that, in order to obtain the movable
contact parts, groups of contact springs must be mounted, (riveted
for example) on the printed circuit board and conductively
connected with the printed circuit. In addition, electrical
disadvantages result from the fact that the slider, when inserted
between the movable contact parts, is subject to heavy wear and, as
a result, the contacts become smeared. Furthermore, this known
slide switch is not suitable for multiple (ganged) switching
functions such as they occur in program controlling systems.
In order to obtain a switch which is capable of performing a
plurality of switching functions, several independent, individual
slide switches have heretofore been assembled into a multiple
(gang) switch by suitably placing one behind the other, as in
German Pat. No. 1,245,475. However, that art does not lend itself
to construction of slide switches or multiple switches intended for
use in printed circuit equipment.
SUMMARY OF THE INVENTION
In consideration of the disadvantages of the prior art, it may be
said to be the general object of the invention to provide a modular
slide switch of particularly low profile design, which can be
mounted on a printed circuit board as an independent part or
included in a multiple switch. In the present invention, the said
slider is slideably inserted in the guide slot of said printed
circuit board and, at one of its ends, provided with at least one
resilient detent arm which slides along said board when the switch
is actuated, and engages with one of a plurality of detent recesses
(slots) in said board for each intended switching position. Since
the slider of insulating material is displaceably arranged and is
inserted through the plane of the insulating plate or circuit
board, the slide switch according to the invention is of
particularly small height (profile). Smearing of the contacts
during the insertion of the slider into the recess of the plate
cannot occur because the movable contact parts are carried by the
slider.
For the slide switch according to the invention, the engaging
(positioning) problem is solved in an especially simple manner
which is characterized in that a detent arm capable of engaging
with recesses in said insulating plate (circuit board) is provided
at said slider. In a preferred embodiment of the invention, this
detent arm is designed in the form of a caliper consisting of two
symmetrical parts of equal length, which are molded to said slider.
This caliper slides above and below, applying a nominal "biting"
pressure to said board. The jaws of this caliper jointly engage the
recess in said board corresponding to a discrete position. In
principle, a one-piece detent arm would be sufficient to afford a
secure detent, however, with a one-piece detent arm, a certain
degree of canting and, consequently, jamming of the sliding contact
can occur. However, the locking pressures of the two parts of the
"caliper" (two-piece) detent arm, (normal to the plane of the
circuit board) on the slider are cancelled if the two caliper parts
are exactly arranged in a mirror-inverted arrangement, i.e.,
symmetrically. This also results in a degree of mechanical stress
relief for the printed circuit board, the latter normally not being
designed to resist wear producing pressures to any great
extent.
The problem of guiding the slider along the plate of insulating
material circuit board is, for the slide switch according to the
present invention, solved in an especially simple manner by
providing for guidance of said slider along the edges of said guide
slot. To this end, according to a further feature of the invention,
at least two resilient tongues lying on opposite slot sides from
each other can be molded to said slider. These tongues engage said
slot with barblike noses and, during a switching movement, slide
along the edges of said slot. Such a snap attachment of the slider
permits an especially simple assemblage of the slide switch on the
printed circuit board.
In order to prevent the slider from being actuated beyond the
intended lock positions during switching movements, an advantageous
feature of the invention is characterized in that at the slider two
pairs of such spring tongues lying opposite each other are
provided. In the direction of actuation they can simultaneously
form the two end stops for the limitation of the switching movement
in both directions.
In order to insure the adaptability of the invention for the
performance of a great variety of switching functions, the slide
switch is, according to a further feature of the invention,
designed so that it can be used both individually and ganged. To
this end, the slider is (at its end opposite the detent arms)
provided with a recess into which the detent arms of a second
slider placed behind it (having the same shape) can be engaged for
the formation of a mechanical connection between both sliders. Thus
the same detent arm design not only fulfills the required detention
function but also will act as a connecting element between two
sliders. In particular, a plurality of sliders, arranged one behind
the other, can be interconnected in this manner. To this end, each
slider has such a recess, and therein a head portion having an
undercut neck where it joins the resilient detent arms, so that,
when placing the individual sliders one behind the other, the
detent arm of the following slider engages the head member and
detents over the said neck and thus provides a connection for
transmitting the switching movement directly to the next slider.
Thus it is possible to compose a multiple (gang) switch on the
building-block principle using independent individual slide
switches which can be made in a simple, standardized manner.
Accordingly, the manufacturing cost of such a multiple switch is
low, particularly because the hitherto required, often quite
complicated and costly special designs are no longer necessary.
Further features and advantages of the invention will be apparent
from the following description of the basic single unit and ganged
embodiments shown in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a bottom view of a slide switch according to the
invention.
FIG. 2 is a sideview of the slide switch of Figure 1 mounted on a
printed circuit board.
FIG. 3 is a sectional view of a multiple switch mounted on a
printed circuit board and consisting of two slide switches of the
type shown in FIGS. 1 and 2, arranged one behind the other.
FIG. 4 is a sectional view taken on parting line 4-4 of Figure
5.
FIG. 5 is a partial flat view of a circuit board useable in the
structure of the invention.
FIG. 6 is a section taken along the parting line 6-6 of the slide
switch shown in Figure 1 after this switch has been mounted on a
printed circuit board.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the description to follow, the structure pointed out will be
found variously in the drawings, not necessarily in order of Figure
numbers.
The reference character 1 designates the printed circuit board on
which the stationary contact parts 2, 2', 2" of the slide switch
are provided as components of the printed circuit. Contact springs
3, which are identical in sliders 4 and 5, slide on the stationary
contact parts 2, 2', 2", serving as movable contacts when the
switch is actuated. These contact parts are appropriately designed
as two-armed double springs and undetachably mounted on the sliders
4 and 5. Electrical continuity between the spring pairs on each
side of the slot 6 is provided within the slider body 4 (or 5) so
that they are capable of connecting the stationary contacts 2 with
2' in one switching position of the slider 4. Similarly, the
contact parts 2 with 2" are interconnected in the other position,
thereby effecting a swtich-over or single-pole double-throw
switching logic.
Since the detailed parts associated with 5 are identical with those
of 4, the description and illustration of such details in
connection with 4, will be understood to also apply to 5.
In order to insure a space-saving design, the slider 4 is axially
slideably seated in a slot 6 of the insulating plate 1. The slider
4 is guided along opposite edges of the slot 6 and portions of the
slider protrude through the plate. Spring tongues 7 and 7' molded
to the slider 4 hold the slideable engagement and prevent
separation of 4 from slot 6. It will be seen that four such spring
tongues with their barblike noses are used, and are arranged by
twos transversely with respect to the direction of actuation, see
FIG. 6 and FIG. 1 where the barblike noses 8 through 8'" are
shown.
The said barblike nose 8 and 8', respectively, which engage the
edges of slot 6, slide along an edge of said slot during a
switching movement. The slider 4 is mounted on the insulating plate
1 simply by being pressed into the slot 6. After the pressing-in
operation, the resilient tongues 7, 7' of the slider 4 spread out
and prevent the slider from falling out of the printed circuit
board 1 by the under-grip the said barbs provide. The resilient
tongues 7, 7' simultaneously act as an end stop for the limitation
of the switching movement in one direction. The other end stop is
formed by the connecting element 12 of the detent arm portion 9'
against 10'.
For the realization of definite switching positions, the sliders 4
and 5 are provided with molded resilient detent arms 9 and 10,
respectively, which slide along the board 1 when the switch is
actuated to engage recesses 11, 11' of the board 1 in the
corresponding switching positions. With regard to the load on the
sliders 4 and 5 and the printed circuit board 1, it is appropriate
to design the detent arms 9 and 10 in two pieces, e.g., in the
shape of a caliper. In this design, both parts 9' and 9" and 10'
and 10", respectively, of the detent arms 9 and 10 can, when the
switch is actuated, slide along above and below the board 1 and
jointly engage by means of a "biting" action with the recesses 11
and 11' of the board in the switching positions. For obtaining
stable switching positions while also reducing the sliding friction
during actuation, the two portions 9' and 9" plus 10' and 10",
respectively, of the detent arms 9 and 10 each have, at their free
ends, a semicircular engaging nose 9"' and 9"" plus 10"' and 10"",
respectively. These engaging noses are adapted to the detenting
recesses 11 and 11' of the circuit board 1.
In addition to the detenting function provided by these resilient
members 9' and 9", an alternative function for these parts is
available. Consider the FIG. 3 view, in this ganged embodiment the
slider 5 is tandem connected to 4. To effect this connection, the
engaging noses 10"' and 10"" of the slider 5 are engaged with an
appropriately designed recess 4' in the slider 4. This recess may
be thought of as a neck, or undercut, in the partly tapered
head-shaped member 13 (also 13' on 5). Thus, the multiple switch
shown in FIG. 3 is obtained, comprising two individual slide
switches 4 and 5 arranged one behind the other. The cross
sectioning lines are spaced differently for better identification
of parts associated with each of the 4 and 5 sliders. Since the
slider 5 also has an identical recess 5' suitable for the
engagement of a detent arm, it is possible to interconnect
additional sliders arranged one behind the other, the detent arm of
each engaging the recess of the preceding slider in the same
manner.
Eyelets 4" and 5", respectively, are molded to the sliders and
provide connections for actuating each individually or to actuate
the assembled sliders 4 and 5 as a unit. It will be noted that the
detent arms of a switch module ganged to another module are spread
laterally more than when they engage detent slots in the circuit
board (see FIG. 3). Accordingly, the engagement retention forces
between 4 and 5 are significantly greater than the detent force
against the circuit board. In connection with a printed circuit, a
slide switch or multiple switch according to the invention can
perform a great variety of switching functions. Production and
assembly costs are extremely low. For example, the insulating plate
carrying the conducting pattern need only be provided with
stationary contact parts 2, 2', 2", a slot 6 for the reception of
the slider four-fifths, and engaging recesses 11 and 11' for the
engagement of the detent arm nine-tenths, while on the side of the
insulating plate opposite the stationary contact parts, other
printed connections for the various circuit components may be
arranged. By suitably designing the printed circuit board, it is
thus possible to carry out a multitude of switching operations
without the requirement for wiring in a separate switch assembly
during equipment manufacture. Moreover, special means for mounting
the slider on the printed circuit board and for ganging sliders are
no longer necessary when the present invention is used. Once the
integral assembly steps are complete, the slide switch or the
multiple switch composed of individual slide switches is ready for
operation. Extraneous shifting is prevented by stops formed of the
mounting tongues 7, 7' and connecting elements 12, 12',
respectively, as has been apparent from FIGS. 3 and 6.
Various modifications and variations within the spirit of the
invention are possible. It is not intended that the scope of the
invention should be limited by the drawings or description, the
latter being only illustrative and typical.
* * * * *