Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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S ~ e c i f i c a t i o n
1 The present invention relat:es to motion sensing
apparatus and more particularly to improvements including
a novel sensor and means for variably controlling the
sensitivity of such ap~aratus.
The motion of a platform upon which the sensor
of the present invention is mounted is sensed by a device
comprising a substantially oPaque inertial element movably
supported unon a concave surface which also is substantial-
ly onaque except for a translucent window area at its
lowest point. The inertial element is of such size as to
cover at least a portion of the window area.
A light source and photocell, shielded from
light other than light from said source, are ~ositioned
on oPposite sides of the window area so that upon
movement of the inertial element over the window area
the amount of light reaching the ~hotocell from the source
will be varied.
Signal emitting means resPond to variations in
the amount of lîght reaching the photocell from the light
source. The magnitude of the light variation capable of
causing the signal emitting means to respond may be changed
by adjustment of a threshhold control means.
The emitted signal may be emnloyed to actuate
any of a variety of warning devices or to control
mechanisms such as valves, etc.
The invention wlll now be described by way
example with reference to the accom~anying drawings,
in which:
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l Figure 1 is a view in section of a motion sensor
forming a part of the apparatus of the present invention.
Figure 2 is a circuit diagram showing the
connection of the sensor of Figure l to the threshhold
control means and signal. emitting means of the present
inventi,on.
The motion sensing apparatus of the present
invention includes a novel motion sensor and signal
emitting means which comprises threshhold control means
adjustable to cause the signal emitting means to respond
to different magnitudes of motion sensed by the sensor.
As shown in Figure 1, the motion sensor com~rises
a packing filled container 10 constituting a base adapted
for mounting, as by legs lOa, on a platform or device the
motion of which is to be sensed. Mounted in the container-
base 10 by ring ll is an assembly comprising an opaque
inertial element 12 disposed within a tubular opaque
carrier 13 presenting at its lower end an interior concave
upper surface 1~ in the form of a portion of a sphere
provided with a transparent central window 15 in its
lowest part.
The inertial element 12 is, in the preferred
embodiment illustrated and described, a globule of mercury
of a size which covers a major part of the area of the
window 15, but for certain uses it may be desirable to
substitute a metal ball for the mercury globule and/or
to size the inertial element to entirely cover the window.
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1 'I`he carrier 13 supports at its upper end a closure 17
of resilient mater:ial such as rubber.. The closure 17 has a
central opening 1,8 seized to receive and retain a light emitting
diode 19 which, when energized from a source of power 27 via
leads 20 to ground (see F'igure 2) projects light axi~lly of the
carrier 13 against the surface 14, window 15 and inertial
element 12.
Secured to the lower end of the carrier 13, preferably
removably, is a cup fitting 21 and positioned centrally within it,
directly under the window 15, is a phototransistor 22. Its
leads 23 pass th,rough a grommeted hole 24 in the cup wall.
This arrangement is such that movement in any generally
horizontal unrestricted direction of the carrier 13 and of the
platform on which the base 10 is mounted will cause movement
of the mercury globule 12 on the spherical surface 14 with
respect to the window 15 and wi.ll thus change the amount of light
from the source 19 which reaches the phototransistor 22. This
produces a detectable output from the phototransistor which
is employed to control signal emitting apparatus.
As shown in Figure 2, the output of the photo-
transistor 22, which is energized via lead 25 connected
through resistor 26 to power supply 27, passes through lead
30 to one input of a comparator 32; the other input of which
is connected via lead 33 to the moving contract of a potent-
iometer 35 the winding of which is connected in series with
resistors 36 and 37 of a voltage divider network. The
compara,or 32 is a differential high gain amplifier which
changes its output from high to low when the voltage of its
input 30 rises above the voltage of its input 33. Thus,
by adjusting the potentiometer 35 to increase the voltage
l in~ut ~ia lead 33, a greater voltage in~ut is required on
lead 30 to change the output of comoarator 32 from high to
low. This arrangement, there~ore, constitutes a threshhold
control means whereby the amount of light Ealling on the
~hototransi,stor 22 which is re~uirecl to ~roduce a change
of state of the com~arator 32 nav be increased or decreased
as desired.
Signal emitting means are controlled by the
comparator 32 to provide a slgnal pulse of adjustable
duration upon a change of state of the com~arator. This
means comprises a NOR gate 40 one input of which is connected
by lead 41 to the outnut of comparator 32 and the other
input of which is grounded through lead 42. This arrangement
is such that when the output of comparator 32 goes from high
to low, a pulse is produced at the output of the NOR gate 40.
The output of NOR gate 40 is connected via lead 43
to a monostable or "one-shot" multivibrator 45 which, in
response to an in~ut pulse on lead 43, emits a pulse on lead
46, the duration of which is controlled by a resistor-
capacitance network 48 inter~osed between the multivibrator45 and a lead 49 connected via lead 27 to the power supply.
The pulse duration may be varied by adjustment of the variable
resistor 50, and the limits of its duration established by
selecting appro~riate values for the resistance and the
capacitance employed. The values shown on the drawing for
these as well as other com~onents are merely typical values.
Means are provided for selectively determining
whether the output pulse of the multivibrator 45 will be
employed directly to actuate a device to be controlled by
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l the motion sensing aP~aratus of the ~resent invention or
whether it will be emploved to set a switching mechanism from
one state to another for actuating such a device. This
means com~rises a double pole single throw switch 52 which
in one position connects its output through resistor 53
via lead 54 directly to the out~ut 46 of multivibrator 45.
In its other ~osition switch 52 connects its output via lead
55 to the output of a bistable flipflop 56 which receives
its input from the multivibrator 45 via lead 46. A reset
switch 60 for flipflop 56 applies an input from the power
27 via leads 49, 61 and 62 to the flipflop to reset it
from a high to a low output.
This arrangement is such that, when switch 52
engages the lead 55 contact, an output pulse from the
multivibrator 45 will invert the flipflop 56 to maintain
an output voltage at the output of switch 52, independent-
ly of the initiating pulse, until the reset switch 60
is closed.
In the preferred embodiment illustrated and
described the output pulse from switch 52 through resis~or
53 is employed to turn on a transistor switching means 65
to apply power from the source 27 via lead 49 to the winding
of a solenoid 67 which may actuate any desired type of
such device, such as a fluid control valve, or act merely
as a relav to control other mechanisms.
~ hile the preferred embodiment of the invention
has been described herein, it will be understood that the
same is susceptible of modification in many particulars
and that the invention is not to be taken as limited to
the embodiment illustrated and described.
