U.S. patent number 3,674,950 [Application Number 05/082,570] was granted by the patent office on 1972-07-04 for self-aligning motion detectors.
This patent grant is currently assigned to American Multi-Lert Corporation. Invention is credited to Andrew E. Scoville.
United States Patent |
3,674,950 |
Scoville |
July 4, 1972 |
SELF-ALIGNING MOTION DETECTORS
Abstract
A motion detector for energizing an alarm signal at a suitable
location and which is responsive to linear motion of an object on
which the detector may be mounted and capable of self-alignment to
the object. The detector comprises a case or suitable enclosure
within which an outer pendulum or pendulum body is supported for
freedom of universal but sluggish movement and within which a
second pendulum or body is supported for universal and
unconstrained movement with respect to the outer pendulum. Contact
is made between respective pendulums or bodies upon motion of the
case to transmit an electrical signal to a suitable sensor, alarm
or the like. The motion of the outer pendulum is suitably
constrained as by immersing it in a liquid within the case or by
providing it with a greater period than the inner pendulum or body
in compound pendulum aspects. A contact ring may be located on the
inner wall of the outer pendulum or other suitable contact means
for electrical contact between the ring and the inner pendulum or
between the contact means to close a control circuit.
Inventors: |
Scoville; Andrew E. (Ellington,
CT) |
Assignee: |
American Multi-Lert Corporation
(Hershey, PA)
|
Family
ID: |
22172009 |
Appl.
No.: |
05/082,570 |
Filed: |
October 21, 1970 |
Current U.S.
Class: |
200/61.48 |
Current CPC
Class: |
H01H
35/02 (20130101); G01P 13/00 (20130101); B60R
25/1006 (20130101); H01H 35/142 (20130101) |
Current International
Class: |
H01H
35/14 (20060101); B60R 25/10 (20060101); H01H
35/02 (20060101); G01P 13/00 (20060101); H01h
035/14 () |
Field of
Search: |
;200/61.45,61.48,61.49,61.51,61.52,166BH,61.53 ;340/261,262 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schaefer; Robert K.
Assistant Examiner: Ginsburg; M.
Claims
I claim:
1. A self-aligning circuit closer comprising a support, an
elongated tubular pendulous contact member extending upright
relative to the support, a horizontal axial support connected to
said tubular member, means for suspending said contact member on an
upright axis for universal movement relative to the first mentioned
support about a center located on said axis, a second contact
member supported on the pendulous contact member by said horizontal
axial support for universal movement relative thereto with a center
of suspension located on said upright axis, said contact members
having different dynamics of motion about the respective centers of
suspension on said axis, and means on the tubular contact member in
position for contact engagement by the second contact member upon
relative swinging movement for closing a circuit therebetween.
2. A circuit closer according to claim 1, wherein the tubular
contact member has a cross member extending transversely between
opposite sides thereof, and means having a supporting connection
with the cross member and forming a universal support for the
respective contact members on a common horizontal axis for freedom
of movement of the contact members relative to each other.
3. A circuit closer according to claim 1, including means for
damping the motion of the tubular contact member.
4. A circuit closer according to claim 1, including a damping fluid
housed in the casing, with the lower end portion of the tubular
contact member extending into the fluid.
5. A circuit closer according to claim 1, including a contact ring
secured to the inner face of the tubular contact member around the
lower end portion of the second contact member and has an irregular
contact face.
6. A circuit closer according to claim 5, wherein the inner face of
the contact ring is elliptical about the second contact member.
7. A self-aligning motion detector comprising an outer tubular
pendulum contact member, a pendulum contact member extending
lengthwise in said tubular member, horizontal axial support
connected to said tubular member, means supporting the respective
pendulum contact members at one end thereof about a said horizontal
axial support for universal movement relative to each other, said
pendulum members having different dynamics of motion about the
centers of suspension thereof for relative motion upon the
application of force thereto, and means forming contact portions
between the members upon relative motion therebetween.
8. A motion detector according to claim 7, including means for
damping the motion of the outer pendulum member.
9. A circuit closer comprising an upright casing, an upright
tubular contact member in the casing, means connected with the
upper end of the tubular contact member mounting said member in the
casing for universal movement relative thereto, a pendulum contact
member extending downwardly in the tubular contact member and
having a contact portion on the lower end thereof, a contact ring
mounted on the inner wall of the tubular contact member surrounding
the contact portion for contact engagement therebetween, and a wire
member extending in bridging relation across the tubular contact
member and having the upper end portion of the pendulum contact
member mounted thereon for universal movement relative to the
tubular contact member.
10. A circuit closer according to claim 9, wherein the contact ring
has the inner face thereof extending elliptically about the contact
portion of the pendulum contact member.
11. A circuit closer comprising an upright tubular contact member,
means connected with the upper end portion of the tubular contact
member mounting said member for universal movement, means forming a
spherical surface in the lower portion of said tubular contact
member, a ball seated on the spherical surface in position for
freedom of rolling contact with an inner contact surface in the
tubular contact member, and means for electrical connection with
the ball and with the inner contact surface and for closing a
circuit therebetween upon rolling motion of the ball into contact
with the inner contact surface.
12. A circuit closer according to claim 11, wherein the tubular
contact member has a conductor rod secured in the lower end portion
thereof and electrically insulated from the tubular contact member,
said conductor rod having the spherical surface on the upper end
thereof.
Description
SUMMARY OF THE INVENTION
This invention relates to improvements in motion detectors for
energizing or controlling a suitable sensor, alarm or monitor
system when the device or object on which the detector is mounted
is subjected to linear motion in any direction.
A motion detector for this purpose must have sensitivity of a very
high order to be effective for signalling motion of the device.
While pendulum switches have been suggested heretofore for
controlling various electric circuits, either they do not have
sufficient sensitivity for the effective performance of the
function required in this environment or, if they do have
sufficient sensitivity, then they require extremely careful initial
alignment to the object on which they are mounted.
One object of this invention is to simplify and improve devices for
controlling electric circuits which will respond effectively to
small but finite motion and indicate by control of an electric
signal to a suitable sensor, alarm or monitor system.
Another object of the invention is to provide an assembly which,
when subjected to initial misalignment, will be self-adjusted to
allow a more sensitive detection of the motion than would be
practical otherwise.
Another object of this invention is to provide means to have
different sensitivity to motion along one axis than along a cross
axis.
Still another object of the invention is to provide in a motion
detector both outer and inner pendulums or bodies, one within the
other, and which respond to motion imparted to their pivot point so
as to maintain their original positions. This causes a forcing
function or drive to initiate swinging of the pendulums. Having
different natural frequencies or periods they will move into
contact with each other closing an electric circuit depending on
the extent of such movement. The inner pendulum or body is designed
for as free motion as possible whereas the outer pendulum is
designed for slower response.
These objects may be accomplished, according to one embodiment of
the invention, by providing an outer case for enclosing a pair of
pendulums, one within the other and both mounted for universal
movement in all directions with respect to each other and relative
to the case. The inner pendulum is disposed so as to make contact
with the outer pendulum or with contact means thereon, thereby to
close an electric circuit to a suitable sensor, alarm or monitor
system for indicating the movement of the device on which the case
is mounted.
THese objects may also be accomplished by an alternate embodiment
wherein the inner pendulum becomes a spherical ball rolling on a
concave curved surface. This curved surface is located near the
bottom of an outer pendulum. The radius of curvature of this
surface determines the effective (or equivalent) length of the
inner pendulum or body so mechanized. The ball seat is electrically
connected to one output terminal and the outer pendulum contact
surface (or ring) is electrically connected to the other terminal
and they are electrically insulated from each other. The ball makes
contact, as before, in response to motion imparted to the outer
pendulum.
The motion constraint of the outer pendulum may be accomplished by
immersing the same in a suitable damping fluid contained within the
case to vary the response time of the outer pendulum. The dynamics
of the pendulums may also be varied by relative adjustment of the
effective length thereof or by compound characteristics of the
outer pendulum.
Sensitivity can also be adjusted by means of a contact ring mounted
within the outer pendulum, the inner diameter of which is then
elliptical so as to vary the sensitivity of the detector along the
two respective axes of the inner surface of the ring. The inner
surface is subject to contact by the inner pendulum or pendulous
body upon relative swinging motion, and the degree of swinging for
contact will be varied according to whether the inner pendulum or
pendulous body strikes along the long or short axes of the
elliptical inner surface.
BRIEF DESCRIPTION OF THE DRAWINGS
This embodiment of the invention is illustrated in the accompanying
drawings, in which:
FIG. 1 is a vertical section through the motion detector;
FIG. 2 is a horizontal section therethrough on the line 2--2 in
FIG. 1;
FIG. 3 is a horizontal section through the pendulums on the line
3--3 in FIG. 1;
FIG. 4 is a vertical section through a circuit closer, showing a
modification;
FIG. 5 is a similar view, showing a further modification;
FIG. 6 is a detailed perspective view, showing a support for the
inner pendulous body;
FIG. 7 is a similar view, showing a modification of the support;
and
FIG. 8 is a vertical section of a further modification.
DETAILED DESCRIPTION OF THE DRAWINGS
The motion detector is capable of being used on any object, the
motion of which it is desired to be indicated or recorded. For
example, it may be used on a suitable transport vehicle, truck or
other conveyance to detect the unauthorized use and movement
thereof. It should be connected with a suitable sensor, alarm or
monitor system which will respond to the action of the detector in
closing an electric circuit. The responsive means is not indicated
in detail, but any suitable form thereof may be used for the
purpose.
The detector comprises a case, generally indicated by the numeral
1, which is adapted to be mounted in a suitable position fixed upon
the device whose motion is to be detected. The case 1 is in the
form of a closed receptacle having a cover 2 thereon for purpose of
access to the case.
Mounted within the case 1 is an upright tubular outer pendulum,
generally indicated at 3. The pendulum 3 is suspended in the case
for freedom of universal movement relative thereto. A suitable
universal joint is shown at 4 illustrative of an appropriate
mounting for the pendulum.
Located within the upright tubular pendulum 3 is an inner pendulum
5 which extends throughout a substantial portion of the length of
the outer pendulum 3, although the relative dimensions may be
varied as found desirable. The inner pendulum 5 is supported on a
universal mounting 6 within the outer pendulum 3 as, for example,
on a support wire 7 extending diametrically across the outer
pendulum 3.
The connection between the inner pendulum 5 and the wire 7 will be
such as to permit of this freedom of motion. If the wire has
sufficient yieldability for freedom of swinging movement of the
inner pendulum 5 relative to the outer pendulum 3, this may be a
fixed connection, but if the support be substantial, it may be in
the form of a universal joint of conventional form.
The lower end of the inner pendulum 5 has a weight 8 or ball
mounted thereon for electrical contact either within the inner face
of the pendulum 3 or with a contact ring 9 mounted therein. The
contact ring 9 is supported by suitable fastenings 10 on the inner
wall of the outer pendulum 3 fitting the surface thereof. For
varying the sensitivity of the device, the inner surface of the
ring 9 may be in the form of an ellipse, as illustrated in FIGS. 2
and 3, so as to register variations according to the direction in
which the inner pendulum swings relative to the outer pendulum
along the short or long axis of the elliptical surface 11.
The control circuit may be connected with the detector through
suitable electrical connections, such as wires 12 and 13 shown as
connected respectively to the ring 9 and the inner pendulum 5.
These wires should be led out through the case 1 in any suitable
manner as, for example, through the universal joint 4.
The motion of the outer pendulum 3 may be suitably damped by
immersing this pendulum in a body of liquid 14 contained in the
bottom of the case 1. The viscosity of the liquid and the height
thereof in the case may be varied as found desirable for variations
in sensitivity and reaction time. It is desired that the liquid
should not extend into the tubular outer pendulum 3 so as to leave
the latter and the pendulum 5 free for relative motion.
Accordingly, the bottom end of the tubular outer pendulum 3 is
shown as being drawn closed and sealed, as indicated generally at
15 in FIG. 1.
It will be apparent that any motion of the supporting device on
which the detector is mounted will result in relative motion
between the outer and inner pendulums and if substantial motion is
involved, will cause a closing of the circuit between the wires 12
and 13 by engagement of the contact member 8 on the pendulum 5 with
the inner surface of the contact ring 9, thereby controlling the
electric circuit to indicate the motion.
The contact ring 9 should be suitably insulated. The outer pendulum
3 may be made of a suitable insulating material such as plastic,
with the conductor contact ring 9 supported on the inner surface
thereof. However, if the outer pendulum 3 is of metal, a suitable
insulating material may be interposed between the surfaces of this
outer pendulum and the contact ring 9.
The inner pendulum 5 will make contact with the outer pendulum or
the contact ring thereon when the device is subjected to linear
motion along any horizontal axis.
The detector uniformly affords self-adjustment to initial set-up
misalignment and provides a more sensitive detector than would be
practical otherwise.
The outer pendulum is constrained to move in a more sluggish manner
than the inner pendulum as by reason of the damping fluid 14
between the outer pendulum and the case or by the compound pendulum
aspects of the dynamics associated with a compound outer pendulum
or variations in relative length between the pendulums, or a
combination of these factors, depending upon the gross sensitivity
and/or the response time to motion at or over the sensitivity
threshold level.
This invention allows adjustable sensitivity. The sensitivity can
be controlled by setting the gap between the inner pendulum and the
outer pendulum. Also the gap and thus the sensitivity for two
orthogonal, horizontal axes can be set independently. For example,
the user may wish to have great sensitivity along one axis; whereas
normal expected motion along a perpendicular to this axis would
cause false firing and thus reduced sensitivity is required.
Sensitivity is also adjusted independently along any two orthogonal
axes, such as the adjustment that will result from the use of a
ring inside the outer pendulum and having an elliptical opening in
position for electrical contact therewith of the inner pendulum
upon relative motion therebetween. By varying the elliptical
configuration, the sensitivity of the detector can be varied along
the two axes independently and along all axes relative to the two
pendulums.
Differential sensitivity may be obtained for this embodiment by
blocking off sections of the contact ring 9 so that the ball has to
behave vigorously and thereby crosscouple some motion to the
sensitive axis before contact will be made in response to motion
along the de-sensitized axis.
Depending upon application, the motion detector may use means to
constrain the movement of the outer pendulum such, for example, as
the damping fluid enclosed in the case and in which the pendulum is
immersed. The device is self-adjusting, especially for misalignment
in mounting.
The outer pendulum corrects any misalignment of the case and always
has its operating center in a vertical direction. Both of the
pendulums respond to gravity, with suitable damping or other
constraint of the outer pendulum as by varying the quantity f
liquid damping fluid or by adding effective length thereof so as to
change the dynamics of motion.
Another form of motion detector that will be self-aligning is
illustrated in FIG. 4. Here the upright case is illustrated at 20
having a top cover 21 and is preferably closed at the bottom for
receiving a body of liquid therein, as described above. This case
may be mounted in any suitable manner upon an object, as also
described above.
Within the case 20 is a cylindrical outer pendulum or pendulous
body 22 having an end cap 23 closing the lower end thereof. This
body forms the outer pendulum and extends upright in the case,
being in the form of a tube closed at the lower end. This outer
pendulum may be mounted in the case 20 for universal movement with
respect thereto as, for example, by the mounting illustrated in
FIG. 6.
Thus, the tubular outer pendulum, which is preferably of
electrically conductive material, has opposite sides of the tube
connected together through a cross shaft 24 with spacers 25 sleeved
thereover inwardly of the opposite walls of the outer pendulum. The
shaft 24 is mounted within an eye 26 loosely thereon capable of
universal movement and which eye 26 is suspended by a bracket
member 27 extending upwardly to and supported by the cap 21 of the
case. This will allow freedom of swinging movement of the outer
pendulum in any direction with respect to the case.
Also suspended from the shaft 24 is an inner pendulum, illustrated
generally at 28. The mounting of the pendulum 28 by a yoke 29 on
the shaft 24 allows freedom of universal movement of the inner
pendulum with respect to the shaft, the holes being sufficiently
enlarged so as to permit of freedom of movement in any
direction.
The outer and inner pendulums 22 and 28 are electrically connected
with terminals 33 on the cover 21 of the case.
The lower end of the inner pendulum may be in position to swing
into electrical conducting relation with the inner surface of the
outer pendulum 22, or a contact plate 28a may be detachably
connected with the lower end of the pendulum 28 for making contact
with the inner surface of the outer pendulum 22. This contact plate
would have a larger outside diameter than the lower end of the
inner pendulum, but may be varied in size or characteristics for
adjustment of the cap and for varying the sensitivity of the
device. The outer and inner pendulums would both be of electrically
conductive material in this illustration.
This form would function substantially as described above with
respect to the form of the invention illustrated in FIGS. 1 to
3.
FIG. 5 shows a further modification in the form of circuit closer
illustrated in FIG. 4 in that the outer pendulum 22 is in the form
of a tube with an end cap 30 that is sleeved into the lower end of
the tube and detachable and removable therefrom so that it may be
replaced with another end cap when it is desired to vary the gap
and the sensitivity of the device.
It will be noted that the lower end of the inner pendulum 28 makes
electrical contact with the inner surface of the cup-shaped end cap
30 that is sleeved into the tubular outer pendulum 22. This
cup-shaped end cap 30 is electrically connected with a terminal 31,
shown in this instance as attached to the bottom of the case 20. A
single terminal 32 is provided on top of the case, electrically
connected with the inner pendulum.
Another form of support for the inner pendulum is illustrated in
FIG. 7 as a modification of the structure shown in FIG. 6. Here the
shaft 35 extends transversely between opposite sides of the outer
pendulum 22 and has a slot therethrough, as indicated at 36.
Mounted in the slot 36 is a ring 37 which may be retained in the
slot, if needed, by a cross pin therein. This ring 37 is
interconnected with an eye of a suspending bracket 38 similar in
character to the bracket 27, described above. Connected with the
opposite side of the ring 37 is a ring 39 fixed to the upper end of
the pendulum 28'. The interconnection provided by the rings 37 and
39 with the bracket 38 and shaft 35 mount both pendulums for
universal movement with respect to the case or support for the
bracket 38. In other respects, the structure operates in the manner
described above.
Another form of motion controller is illustrated in FIG. 8. Here
the case is formed by a surrounding wall 40 having top and bottom
end caps 41 and 42. These parts preferably are formed of a suitable
plastic material and are secured and sealed together in
conventional manner. They may contain a body of liquid if
desired.
Located within the wall 40 of the case is an outer pendulum,
generally illustrated at 43, preferably tubular in form and made of
a suitable electrically conductive material. The tubular outer
pendulum 43 is closed at the bottom by an end cap 44 which may be
in the form of a rod of electrically conductive material and
insulated from the outer pendulum 43 by a suitable insulating
material 45.
The upper end of the end cap 44 has a spherical surface 46 upon
which is seated a ball 47 of electrically conductive material. The
lower end of the end cap 44 is electrically connected through a
wire 48, with a terminal 49 mounted in the end plate 42 of the
case.
The outer pendulum is suspended by a rod 50 which extends
diametrically across opposite sides of the tubular outer pendulum
43 with a reduced intermediate portion 51 in the rod. This reduced
portion 51 extends through an eye in a suspending bracket or hook
52 loosely with respect thereto, which bracket or hook 52 extends
up to a terminal 53 mounted in the end plate 41 of the case.
It will be apparent that the outer pendulum 43 is suspended for
universal movement with respect to the case about a center within
the parts 51 and 52 and responds to variations in motion imparted
to the case. The outer pendulum 43 is of electrically conductive
material and thus will be connected electrically to the terminal
53. The ball 47 forms a pendulous body freely and loosely suspended
upon the spherical surface 46 so as to respond in movement to
vibrations or motion imparted to the case and to the pendulum 43 so
as to make contact with the inner surface of the latter upon such
relative motion. This ball 47 is electrically connected to the
terminal 49 through the end cap 44, and these parts therefore form
a circuit closer for a circuit connected with the terminals 49 and
53.
In other respects this form of the invention operates in the manner
described above and for the purposes herein set forth.
Some applications of this invention are to mobile objects to detect
motion over a predetermined threshold of trucks, trailers, railroad
cars, airplanes, boxes, equipment; also to stationary structures to
detect motion over a predetermined threshold, as fences, walls,
doors, bridges, buildings. These are given as examples, and the
invention may be applied in many other ways.
While the invention has been illustrated and described in certain
embodiments, it is recognized that other variations and changes may
be made therein without departing from the invention set forth in
the claims.
* * * * *