U.S. patent number 3,630,150 [Application Number 04/869,487] was granted by the patent office on 1971-12-28 for actuating mechanism.
This patent grant is currently assigned to The Singer Company. Invention is credited to Edward L. Rakowsky.
United States Patent |
3,630,150 |
Rakowsky |
December 28, 1971 |
ACTUATING MECHANISM
Abstract
An actuating mechanism in which a source of fluid is directed
against an end wall of a rigid body portion having an open cavity
formed therein to create pressure waves of fluid which pass through
the length of the cavity to the closed end thereof to cause a
temperature rise at the closed end. This temperature rise is
utilized to ignite an explosive device which, in turn, is utilized
to accomplish work.
Inventors: |
Rakowsky; Edward L. (Kinnelon,
NJ) |
Assignee: |
The Singer Company (New York,
NY)
|
Family
ID: |
25353629 |
Appl.
No.: |
04/869,487 |
Filed: |
October 27, 1969 |
Current U.S.
Class: |
102/205; 89/7;
89/1.14; 102/224 |
Current CPC
Class: |
F42C
15/31 (20130101); F42C 15/29 (20130101); F02K
9/95 (20130101); F05D 2260/99 (20130101) |
Current International
Class: |
F42C
15/29 (20060101); F42C 15/31 (20060101); F42C
15/00 (20060101); F02K 9/95 (20060101); F02K
9/00 (20060101); F42c 005/00 () |
Field of
Search: |
;102/70,81,49.7,27 ;89/7
;124/11,13 ;60/26.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Engle; Samuel W.
Claims
I claim:
1. An actuating mechanism comprising a first rigid body portion
having a longitudinal axis having a cavity formed therein coaxially
therewith, said cavity having an open end and a closed end, means
to direct a source of fluid against a wall of said first body
portion and towards said open end to create pressure waves of fluid
which pass through the length of said cavity to said closed end to
cause a temperature rise at said closed end, and means responsive
to said temperature rise for accomplishing work, wherein said means
to direct a source of fluid against the wall of said first rigid
body portion includes a second rigid body portion fixedly connected
to said first rigid body portion, said second rigid body portion
having a longitudinal passage connected to said cavity coaxially
therewith, said second rigid body portion having a transverse
passage connected to said longitudinal passage and to said cavity
and extending transverse to said longitudinal passage, said second
rigid body portion having a radially outer surface, said
longitudinal passage having a converging end portion having an
outlet opening, said outlet opening facing said cavity open end
coaxially therewith, said transverse passage having a radially
inner inlet end disposed adjacent said cavity open end and having a
radially outer outlet end having a vent opening extending through
said exterior surface.
2. The mechanism of claim 1 wherein said means for accomplishing
work comprising an explosive charge in heat exchange relation with
said closed end, said temperature rise causing said explosive
charge to ignite, and wherein said actuating mechanism is a
one-piece rigid housing arranged so that said first rigid body
portion and said second rigid body portion are axially spaced
portions thereof, and wherein said transverse passage is disposed
substantially at right angles to said longitudinal passage, and
wherein said first body portion has an axially outer end face
having a recess receiving said explosive charge forming said cavity
closed end.
Description
BACKGROUND OF THE INVENTION
The invention herein described was made in the course of or under a
contract or subcontract thereunder, with the Department of the
Army.
This invention relates to an actuating mechanism and, more
particularly, to such a mechanism utilizing a fluidic device to
produce thermal energy.
Many existing actuating mechanisms employ electrical devices, such
as spark gaps or resistance wires, which require electrical inputs.
For example, the igniter for an oil burner in a home heating system
uses a high-voltage spark gap. Also, on many aerospace and
ordinance systems it is desirable to initiate operations from a
remote location, in which case pyrotechnic devices are used and the
igniter thereof is energized by a hot resistance wire. Further,
explosive-actuated valves, as well as solid grain hot gas
generators, normally utilize an electrical initiated squib or
exploding bridge to trigger the explosive charge. However, due to
the low-power consumption of the electrical igniter in these
devices, false triggering can be induced by lightning, static
electricity, radiofrequency interference, nuclear radiation,
etc.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an
actuating mechanism which is free from electrical components and
connections, and which therefore eliminates the above disadvantages
associated with an electrical actuating mechanism.
Toward the fulfillment of this object, the actuating mechanism of
the present invention comprises a rigid body portion having a
cavity formed therein, said cavity having an open end and a closed
end, means to direct a source of fluid against an end wall of said
body portion and toward said open end to create pressure waves of
fluid which pass through the length of said cavity to said closed
end to cause a temperature rise at said closed end, and means
responsive to said temperature rise for accomplishing work.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference is now made to the accompanying drawings for a better
understanding of the nature and objects of the present invention.
The drawings illustrate the best mode presently contemplated for
carrying out the objects of the invention and are not to be
construed as restrictions or limitations on its scope. In the
drawings:
FIG. 1 is a cross-sectional view depicting the actuating mechanism
of the present invention used in conjunction with a valve; and
FIG. 2 is a view similar to FIG. 1 but showing the actuating
mechanism of the present invention used in conjunction with a hot
gas generator.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring specifically to the embodiment of FIG. 1, the reference
numeral 10 refers to a housing in which a nozzle 12 is formed
having an internally threaded entrance 14 adapted to accommodate a
corresponding externally threaded tube or the like (not shown) for
the introduction of pressurized fluid, such as gas, into the nozzle
in the direction indicated by the arrow. The exit end of the nozzle
12 converges as shown, and communicates with an opening 16 formed
in the housing 10.
A tubular resonance cavity 18 is formed in a rigid body portion 19
of the housing 10, and the entrance to the cavity 18 communicates
with the opening 16. The other end of the cavity 18 is closed by a
pyrotechnic explosive 20, in the form of a lead azide, or other
similar material, which is adapted to ignite upon the latter end
portion of the cavity 18 reaching a certain temperature, as will be
explained in detail later.
An additional housing 21 is provided which has one end threadably
engaging end of the housing 10, and two chambers 22 and 24 formed
therein. A piston 26 is reciprocally mounted in the chamber 22 with
the stem of the piston slideably extending through a partition 28
formed through the housing 21 and into the chamber 24. A guillotine
30 is formed on the other end of the stem in the chamber 24 and is
disposed in proximity to a diaphragm 32 extending across the
chamber 24 and adapted to prevent flow of an additional fluid
through the chamber 24 from an inlet port 34 to an outlet port
36.
In operation, pressurized fluid, such as gas, is introduced into
the nozzle 12 and flows outwardly therefrom into the opening 16 in
the direction indicated by the arrows, whereby a small portion
enters the cavity 18 and the remaining portion impinges upon the
front wall of the body portion 19 and exits from the system in a
direction at right angles to the direction of flow into the cavity
18. After a very short time the cavity fills up and the entire flow
impinges off of the wall and exits from the housing. In this manner
an unstable wave will be formed at the entrance to the cavity 18,
which wave oscillates back and forth and causes small pressure
waves to travel the length of the cavity 18 and compress the gas
trapped at the closed end thereof, thus adding energy to the gas at
every cycle of oscillation. Accumulation of this energy input per
cycle causes the temperature at the closed end of the cavity 18 to
rise appreciably to a point whereby it ignites the explosive
20.
The thermal energy thus created drives the piston 26 in a direction
from left to right as viewed in FIG. 1, and causes the guillotine
30 to sever the diaphragm 32 and thus permit flow of the additional
fluid from the inlet port 34 through the chamber 24 and out the
outlet port 36.
It is thus seen that an effective valve is formed in the chamber 24
which is actuated by gas flow into the nozzle 12, while all
electrical components and connections are eliminated.
In the embodiment of FIG. 2, a housing is provided which is
identical to the housing 10 of the embodiment of FIG. 1 and
therefore will not be described in detail. As in the previous
embodiment, a pyrotechnic explosive 20 closes the exit end of the
cavity 18 formed in the housing 10.
According to this embodiment, an additional housing 40 is
threadably engaged to an end of the housing 10, and houses a solid
grain propellant 42 which may be in the form of an ammonium
perchlorate. The propellant 42 is cast in the form of a tube having
a hollow portion 44 and is adapted to be ignited by the thermal
energy created by the explosive charge 20, to produce a hot gas. In
this manner, upon the temperature at the closed end of the cavity
18 reaching a temperature sufficient to ignite the explosive charge
20, the thermal energy created ignites the solid grain propellant
42, and generates the hot gas which passes from the housing 40
through an outlet port 46. The presence of the hollow portion 44 in
the propellant 42 aids in the distribution of the thermal energy to
the propellant 42 and in the flowing of the hot gas to the outlet
port 46. The hot gas thus created may be used for many
applications, such as to ignite a rocket engine, etc.
It is noted that, in each embodiment, the flow from the nozzle 12
can be supersonic, in which case the wave created at the entrance
to the cavity 18 will be a shock wave.
It is thus seen that, by use of the actuating mechanism of the
present invention, electrical inductions and other cross-coupling
inputs from an adverse environment are eliminated, as well as the
cost and vulnerability of spark gaps to outside weather
environments. Also, since high-pressured air is normally readily
available, the mechanism is relatively inexpensive in
operation.
It can be appreciated that several variations in the above
embodiments are possible without departing from the scope of the
invention. For example, although the cavity 18 has been shown with
a cylindrical cross section, it is understood that it can take
other configurations such as rectangular, conical, etc. Also,
various alternate configurations of the nozzle 12 may be employed
such as a convergent-divergent type, and various stagings of the
flow of the gas can be utilized.
Of course, other variations of the specific construction and
arrangement of the mechanism disclosed above can be made by those
skilled in the art without departing from the invention as defined
in the appended claims.
* * * * *