U.S. patent application number 14/752977 was filed with the patent office on 2016-01-28 for electrical setback detection switch.
This patent application is currently assigned to OMNITEK PARTNERS LLC. The applicant listed for this patent is Jahangir S. Rastegar. Invention is credited to Jahangir S. Rastegar.
Application Number | 20160025473 14/752977 |
Document ID | / |
Family ID | 55166502 |
Filed Date | 2016-01-28 |
United States Patent
Application |
20160025473 |
Kind Code |
A1 |
Rastegar; Jahangir S. |
January 28, 2016 |
Electrical Setback Detection Switch
Abstract
A switch including: a first body having holes located at a
longitudinal position; a movable second body having a concavity
corresponding to the holes; a retaining ball positioned in the
holes and corresponding concavity for restraining the second body
from movement relative to the first body; an elastic element
disposed on the body; a mass disposed on the elastic element, the
mass moving the elastic element upon an acceleration event; and
first and second electrical contacts positioned on the body such
that when the acceleration event has a predetermined magnitude and
duration, the mass moves past the longitudinal position to permit
the retaining ball from releasing from the holes, thereby
permitting the second body to move towards the first and second
electrical contacts; wherein the second body includes a conductive
portion for closing an electrical circuit between the first and
second electrical contacts.
Inventors: |
Rastegar; Jahangir S.;
(Stony Brook, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rastegar; Jahangir S. |
Stony Brook |
NY |
US |
|
|
Assignee: |
OMNITEK PARTNERS LLC
Ronkonkoma
NY
|
Family ID: |
55166502 |
Appl. No.: |
14/752977 |
Filed: |
June 28, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62027748 |
Jul 22, 2014 |
|
|
|
Current U.S.
Class: |
102/216 |
Current CPC
Class: |
F42C 15/24 20130101;
F42C 15/20 20130101; F42C 15/40 20130101 |
International
Class: |
F42C 15/24 20060101
F42C015/24 |
Claims
1. A switch comprising: a first body, the first body having one or
more holes located at a longitudinal position of the first body; a
second body movable relative to the first body, the second body
having a concavity corresponding to each of the one or more holes;
a retaining ball positioned in each of the one or more holes and
corresponding concavity for restraining the second body from
movement relative to the first body; an elastic element disposed on
the body; a mass disposed on the elastic element, the mass moving
the elastic element upon an acceleration event acting on the first
body; and first and second electrical contacts positioned on the
body such that when the acceleration event has a predetermined
magnitude and duration, the mass moves past the longitudinal
position to permit the retaining ball from releasing from the one
or more holes, thereby permitting the second body to move towards
the first and second electrical contacts; wherein the second body
includes a conductive portion for closing an electrical circuit
between the first and second electrical contacts.
2. The switch of claim 1, further comprising a casing for enclosing
the body.
3. The switch of claim 1, wherein the one or more holes comprises
three holes.
4. The switch of claim 1, wherein the elastic element is a helical
spring.
5. The switch of claim 4, wherein the mass is one of a solid
portion of the helical spring or a more closely wound portion of
the helical spring than other portions of the helical spring.
6. The switch of claim 1, wherein the elastic element is a first
elastic element and the switch further comprising a second elastic
element for biasing the second body towards the first and second
electrical contacts.
7. The switch of claim 1, wherein the conductive portion has a
shape for mating with a shape of the first and second electrical
contacts.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of earlier filed
provisional application No. 62/027,748 filed on Jul. 22, 2014, the
entire contents of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present disclosure relates generally to electrical
switches, and more particularly, to electrical setback detection
switches used in munitions.
[0004] 2. Prior Art
[0005] Electrical setback switches are used, for example, in
munitions to close or open an electrical circuit upon detection of
an acceleration profile, usually indicated by a nominal peak
setback acceleration level and its duration.
[0006] Currently available devices, usually called G-switches, only
detect the peak acceleration for switching action without any
measure of the peak acceleration duration. In many munitions and
other similar applications (such as in machinery), the device may
be subjected to high peak acceleration due to accidents such as
dropping on a hard surface or impact by other hard objects, which
could trigger switching.
SUMMARY OF THE INVENTION
[0007] Accordingly, a switch comprising: a first body, the first
body having one or more holes located at a longitudinal position of
the first body; a second body movable relative to the first body,
the second body having a concavity corresponding to each of the one
or more holes; a retaining ball positioned in each of the one or
more holes and corresponding concavity for restraining the second
body from movement relative to the first body; an elastic element
disposed on the body; a mass disposed on the elastic element, the
mass moving the elastic element upon an acceleration event acting
on the first body; and first and second electrical contacts
positioned on the body such that when the acceleration event has a
predetermined magnitude and duration, the mass moves past the
longitudinal position to permit the retaining ball from releasing
from the one or more holes, thereby permitting the second body to
move towards the first and second electrical contacts; wherein the
second body includes a conductive portion for closing an electrical
circuit between the first and second electrical contacts.
[0008] The switch further comprising a casing for enclosing the
body.
[0009] The one or more holes can comprise three holes.
[0010] The elastic element can be a helical spring. The mass can be
one of a solid portion of the helical spring or a more closely
wound portion of the helical spring than other portions of the
helical spring.
[0011] The elastic element can be a first elastic element and the
switch can further comprise a second elastic element for biasing
the second body towards the first and second electrical
contacts.
[0012] The conductive portion can have a shape for mating with a
shape of the first and second electrical contacts.
[0013] Unlike the prior art switches, the electrical setback
switches disclosed herein switch, not only when a prescribed
setback acceleration has been reached, but also when the peak
acceleration has a certain minimum duration. For example, if the
setback acceleration is 1000 Gs for a minimum duration of 5
milliseconds, then the present electrical setback switches will
switch and close a circuit when subjected to such a setback
acceleration profile (impulse level). However, for example, if the
switch is subjected to even 2,000 Gs but for a shorter duration of
0.5 millisecond, then it would not switch.
[0014] Such electrical switches can also be used in any device and
machinery which may be subjected to certain shock (relatively high
acceleration) loading that lasts at least a prescribed length of
time. In many devices and machinery high G shock loading that is
very short duration would not cause damage or trigger other
unwanted events. But currently available G-switches would trigger
even when the shock duration is very short. The disclosed switches
overcomes this shortcoming of G-switches and can be designed to
switch at a prescribed peak acceleration as well as its
duration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] These and other features, aspects, and advantages of the
apparatus and methods of the present invention will become better
understood with regard to the following description, appended
claims, and accompanying drawings where:
[0016] FIG. 1 illustrates a cross-sectional view of an embodiment
10 of the electrical setback switch.
[0017] FIG. 2 illustrates an isometric view of the switch of FIG.
1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The cross-sectional view of an embodiment 10 of the
electrical setback switch of the present invention is shown in FIG.
1 (FIG. 2 shows an isometric view of the switch of FIG. 1 showing
an exemplary circular cross section of the switch). The electrical
setback switch 10 consists of a main body 11 and a casing 12, which
is fixedly attached to the body around its base 13, for example
welding, soldering or using adhesives or by press fitting or the
like, depending on the size, application and the setback
acceleration level to be experienced.
[0019] The body 11 of the electrical setback switch 10 is provided
with a cylindrical section 14, over which a machined helical spring
15 is provided. The machined helical spring 15 is preferably
fabricated with more than one strand for increased lateral
stability. The machined helical spring 15 is provided with a top
solid wall section 19 (or more closely wound portion as compared to
the remaining portions of the helical spring). Alternatively, the
top solid wall section 19 may be replaced with a separate mass.
Close to the top of the main body 11 is provided at least one hole
18 and preferably three holes 18 around the diameter of the main
body for insertion of balls 17. The balls 17 are positioned inside
the holes 18 and held in place on one side by the inner wall 16 of
the upper solid wall section 19 of the machined helical spring 15
and on the other side by the mating dimples 20, provided in the
element 21, which is constructed to travel easily inside the
cylindrical hole 22 inside the main body 11. As a result, in the
configuration shown in FIG. 1, the element 21 is locked to the
cylindrical section 14 of the body 11 by the at least one ball 17.
The inner surface of the top solid wall section 19 of the helical
machined spring 15 may be provided with a groove 23 within which
the ball 17 can ride, and which runs all the way to the top surface
24 of the helical machined spring 15.
[0020] The element 21 is also provided with a head portion 25,
which is provided with a step reduction 26 in the diameter in the
mid-section as shown in FIG. 1. A preloaded compressive spring 27
is positioned between the surface of the step 26 and the retaining
ring 28 provided inside the cylindrical hole 22 inside the main
body 11. A retaining washer 29 may also be provided between the
preloaded compressive spring 27 and the retaining ring 28 to better
support the spring force.
[0021] Two conductive elements 30 and 31 which are protected inside
thin layers of insulating material (not shown) are mounted inside
the openings 32 and 33, respectively, provided on the base of the
main body 11 as shown in FIG. 1. The two conductive elements 30 and
31 are provided with curved surfaces 34 and 35, respectively, which
are preferably spherical surfaces and match the surface 25 of the
element 21. On the opposite side, the conductive elements 30 and 31
are connected to the wires 36 and 37, respectively, which are
insulated to prevent electrical contact with each other as well as
with the main body 11.
[0022] In operation, when the object (platform) to which the
electrical setback switch 10 is mounted is accelerated in the
direction of the arrow 38, the acceleration would act on the top
solid wall section (mass) 19 of the helical machined spring 15,
causing it to deflect downwards, i.e., in the opposite direction as
the arrow 38. In general, the helical machined spring 15 is
preloaded against the inside surface of the top surface 39 of the
casing 12 so that until a certain level of acceleration is reached,
the top solid wall section 19 of the helical machined spring 15
would not begin to displace downward. However, if the prescribed
level of acceleration in the direction of the arrow 38 is reached,
then the top solid wall section 19 of the helical machined spring
15 will begin to travel downward. Now if the acceleration level
persists for long enough amount of time within the design
specifications of the electrical setback switch 10, i.e., if the
so-called all fire condition has been reached, then the top solid
wall section 19 of the helical machined spring 15 would travel down
enough to clear the balls 17 to be pushed out of engagement with
the dimples 20 by the forces exerted by the surfaces of the
dimples, thereby freeing the element 21 to travel downward. The
preloaded compressive spring 27 will then force the surface 25 of
the element 21 to come into contact with the conductive surfaces 34
and 35 and be pressed against the conductive surfaces by the
biasing spring 27. As a result, the circuit to which the wires 36
and 37 are connected is closed. On the other hand, if the duration
of the acceleration in the direction of the arrow 38 is not enough
even in the presence of higher peak acceleration level, i.e., under
no-fire conditions, the top solid wall section 19 of the helical
machined spring 15 will not travel down enough to release the
locking balls 17 and thereby the element 21 remains locked to the
main body 11 of the electrical setback switch 10.
[0023] It is appreciated by those skilled in the art that the
helical machined spring 15 may be machined in any pattern other
than helical as long as it provides the desired axial stiffness and
equivalent axial inertia to achieve the desired deformation
response to the prescribed axial acceleration level.
[0024] While there has been shown and described what is considered
to be preferred embodiments of the invention, it will, of course,
be understood that various modifications and changes in form or
detail could readily be made without departing from the spirit of
the invention. It is therefore intended that the invention be not
limited to the exact forms described and illustrated, but should be
constructed to cover all modifications that may fall within the
scope of the appended claims.
* * * * *