вход по аккаунту


Патент USA US2107936

код для вставки
Feb. s, A1931s.
‘Wed July 24, 1956
Patented Feb. 8, 1938
George F. Gardner, Scotia, N. Y., assigner to Gen
âralkElectric Com
, a corporation off New
Application July Z4, `1936, Serial No.-9Z,433
2 Claims. _ (Ci. 116-114)
My invention relates to electrical instruments
and concerns particularly indicating instruments
of the light-.beam type.
It is an object of my invention to provide a
5 .suppressed-zero instrument having an arrangement for indicating the zero position and permit- _
ting zero adjustment ‘ of the instrument mechanism.
It is a further object of my invention to pro-
lo vide a compact light-beam instrument with a
is a schematic diagram representing a side eie
vation of the working parts 01' the apparatusof
Fig. 5. Like parts are designated by like reier- '
ence characters throughout in the drawing.
Referring now more in detail to the drawing,
the apparatus of Figs. 1 to 4 comprises a light
tight box II with a front wall I2 having a lwixu‘low
occupied by a translucent screen I3 marked with
suitable graduations and numerals to serve- as an;
indicating scale. Within the light tight box II. lo
relatively great scale rangeV and high target
there is a light-directing tue Il containing a
clarity. _
source of light, such as an incandescent lamp I5,
Still another object of my invention is to pro_ vide a light-beam instrument having a multiple
15 set of graduations passed over successively by
for projecting a beam oi' light I6. An instrument
mechanism I1 having a suitable deilecting ele
ment, such as a coil (not shown), carries amir- l5
the indicating target.
ror I8 intersecting the path of the light beam IE.
Other and further objects and vadvantages will The mirror I8 is adapted >to reñect a beam It
become apparent as the description proceeds.
along the course I9 and the portion I8 of the
In carrying out my invention in its preferred light beam is adapted to deflect back and forth
form, I provide a light-beam instrument with a across the scale I3 in accordance with deflection w
moving element capable of deñecting its light _ of the movable element I8 caused by variations
beam through-a greater angle than that subtend- _ in the magnitude of the quantity being measured.
ed by the scale or the translucent screen of the
instrument and the clarity of the graduations,
the arrangement is such that, as the measuredv 25
such that the beam would otherwise go oi’f the
end of the scale, I provide an auxiliary mirror
or reflector which may be stationary or -may be
quantity increases from zero to a predetermined
value, the beam I9 remains on’ the scale 'Il and
does not approach the lower end of the scale
carried by the movable element.
In order to increase the compactness of the
instrument: For bringing the beam back on the
scale when deilection oi the movable element is
The invention will-be understood more readily
until a predetermined value is reached, thus
forming a suppressed-zero instrument. This ar
from the following detailed description when
rangement also permits keeping the deñection
considered in connection with the accompanying
drawing and those >features of the invention
angle of the beam small enough to insure a clear
.and sharply focused light spot at any position on
_ which are believed to be novel and patentable
the scale.
In the arrangement illustrated, the
will be pointed out in the claims appended heret0- In the drawing. Fig. 1 is a schematic dia.gram representing a plan View of the working
instrument has a full-scale reading of twenty 35
and is` adapted tomeasure values between ten
and twenty, the values below ten being sup
parts of a suppressed-zero instrument constitut-
ing one embodiment of my invention and show40 ing the movable element in its zero position; Fig.
3 `is a front elevation showing the scale of the
Inasmuch as indicating instruments vare sub
ject to certain secular errors which cause varia- m
tions in the zero position and, consequently, con
- apparatus of Fig. 1 with a scale reading for the
stant errors at every scale point, it is customary
condition represented in Fig. 1; Fig. 2 is av dia-
to provide zero-adjusting mechanism for bring
gram of the'same apparatus shown in Fig. 1 with ing the indication back to zero when the meas
the moving element in the position correspond- ured quantity is known to be zero; for exam
ing to the lowest reading of the scale of the in- ‘ple, in the case- oi' an ammeter, when the meter
strument; Fig. 4 is another front elevation show- is disconnected. However, ln the case of sup
ing» the scale of the instrument with a scale read- pressed-zero instruments, this check on the ad
ing for the condition represented in Fig. 2;*Fig. justment is not available and, in the case oi’
50 5 is a, schematic diagram representing a- plan secular changes in the instrument or inadvertent
'view of the working parts of .another embodi- or unauthorized manipulation of the -zero ad
ment of my invention provided with a double tier justment, there is no way of checking the instru
of scales for increasing the scale yrange of the ment except by recalibration of the scale. In
instrument; Fig. 6_is a front elevation o_f the ap- order to overcome this diillculty, I provide an
55 paratus >of Fig. 5 showing the scale; and Fig-` '1 auxiliary mirror . 2n placed in the part of the
box where it will intercept the portion I9 of the
light beam when the movable element I8 is inV
the zero position. The mirror 20 is placed at
such an angle thatfit reflects the beam I9 along
a line 2l to strike the scale I3 at a suitable point,
In the speciiic arrangement illustrated, the
scale I3' has an upper tier of graduations 2B for
numerical values from zero to fifteen and a lower
tier of graduations 26 for -numerical values from
fifteen to thirty. The movable mirrors Il and
24 are placed at such angles that, as the instru
for~ example, the minimum scale. value, ten, ment I1 deñects through the angle correspond
which is accordingly also marked zero.v If the ing to the readings between zero and fifteen, the
spot of light 22 produced on the scale I3 by the mirror.“ reilects a light beam I6' to produce a.
light beam does not coincide with the position movable beam I9' `forming a light spot 22' mov 10
ing back and forth along the tier of graduations
10 of the zero graduation when the instrument is
disconnected from the electrical‘circuit which it 25 of the scale I3’. The mirror I8 reflects a light
is measuring, its zero adjustment, not shown, is beam I6 to produce a movable beam I8 casting
manipulated to bring the light spot 22 tothe a light spot 22" moving across the lower tier 26
proper position. When the measured value rises of the scale I3'. In the arrangement shown, the
appreciably above zero, the beam Ialeaves the upper tier 25 carries the graduations for the
mirror 20 and no light spot appears on the scale lower half of the range of the instrument and
I3 until the minimum value, ten of the scale is the tier 26 carries the graduations for the upper
To guard against mistaking a zero indication half of the range of the instrument.
The invention, of course, is not limited to this 20
for the reading Ill, a color illter, for example, a
arrangement. It will be observed that
red filter 23. may be interposed in the pathof. the mirrors I8 and 24 are not only at an angle
the light beam between the mirrors I8 and 20 or
to each other with respect to the axis of the
, between the mirror 20 and the scale I3. A zero
reading may also be distinguished from a ten moving element of the instrument I1 but are 25
also slightly tilted so that they produce light
25 reading by slightly tilting the mirror 20 so that
spots 22' and 22" traveling in different parallel
it causes a light spot to appear above' or below
In this Way, am' confusion is prevented
the line along which the light spot would travel lines.
the reading observed is within the
for readings from ten to twenty. If desired, in
or upper range of the instrument.l As a
stead of placing the auxiliary mirror 20 at a lower
stationary position in the light box II, it may further safeguard against any such confusion,
of different colors, for example, a red fil
be mounted on the movable element I8 at the filters
ter 21 and a green filter 28 may be provided
proper angle, as explained more in detail in con
nection with Fig. 5. Although the arrangement for the movable beams I9' and I9, respectively,
cooperating with the two different tiers of the
of Fig. 1 finds its principal use as a suppressed
scale I3'. If the color iilters are utilized for
zero instrument, it will be understood that, by distinguishing the movable beams in the two
making the mirror 20 _of suiñcient length or by
providing a number of auxiliary mirrors corre
sponding to the mirror 20, -the light spot 22
produced by the reflected beam 2i may be
4.0 caused to traverse the scale I3 for an appreciable
distance, thus extending the range of readings
which may be made with the scale I3 by utiliz
ing light spots produced both by the beam I9
reflected directly from the mirror I8 and the
2i reflected from the mirror 20. It will be
45 beam
apparent that the use of a stationary auxiliary
mirror 2_9 will cause the beam 2I to deñect in the
opposite `direction from the beam I9, whereas
mounting the auxiliary mirror on the movable ele
ment would cause the beams corresponding to the
two ranges of measurement to deflect in the same
The arrangement of Fig. 5 is intended pri
marily for increasing the range of deflection of
55 a. light-beam instrument without lessening the
compactness of the apparatus and clearness of
the light-spot target. It will be seen that the
translucent screens I3 of Figs. 2 and 3 and I3’
of Fig. 6 subtend an angle oi approximately
60 371/2 degrees whereas deñecting instruments of
the moving coil and other types may readily be
produced having angular deñections of 90 or
more degrees. Furthermore, the reilection of the
beam by the moving mirror makes the angle of
85 deñection of the movable beam double the angle
of deflection of the instrument element, conse
quently, in the ordinary single-range light-beam
instrument, there is a large angle of deñection
of the instrument element which is unused. To
ranges of the instrumen , additional mirrors
may be provided for reflecting the beams on to
the same line of the scale I3' in cases where
such additional compactness may be of value. If 40
desired, the arrangement may be such that the
values oi the graduations in the tiers 25 and 20
of the scale I3’ overlap to a certain extent in
order to check one tier against the other. For
example, in the arrangement shown, the value 45
fifteen appears on both tiers 25 and 26.
As already explained, if a greater scale range
is desired, that is, a greater spacing of the gradu
ations in each portion of the scale, this may be
accomplished by providing additional movable 50
mirrors and additional tiers in the scale Il’. The
arrangement is of particular value in' certain
applications such as tachometer indicators for
ilight testing of aircraft engines, in which a long
scale is required in order to estimate true engine 55
speed closely but which must occupy a minimum
In some cases, no readings are required
for the lower portion of the scale and the gradu
ations from one to fifteen may be omitted, re
taining only the zero graduation to facilitate ad 60
justing the zero of the instrument as explained
in connection with Figs. 1 and 3.
I have herein shown and particularly described
certain embodiments of my invention and cer
tain methods of operation embraced therein for 65
the purpose of explaining its principle and show
ing its application but it will be obvious to those
skilled in the arty that many modiiications and
variations are possible and I aim, therefore, to
cover all such modiñeations and variations as 70
70 make use of this unused angle of ' deiiection, I
fall within the scope of my invention which is
provide a scale or translucent screen I3’ having
deñned in the appended claims,
two or more tiers or rows of graduations and I
What I claim as new and desire to secure by
provide two or more mirrors it and 24 carried ,œ
by the moi/able element ci the instrument meQh
anism il at angles to each other.
Letters Patent of the United States is:
l., An indicating instrument oi the light-beam 75
type comprising in combination, a source of light,
a movable element carrying a pair of mirrors co
operating with said light source to cause beams
of light to be reiìected in response to deñection
2. An indicating instrument of the light-beam
type comprising in combination, a source of light,
a movable element carrying a pair of mirrors co
, of the movable element, a scale-cooperating with operating with said light source to cause beams
said light source and said mirrors so as to be of light to be deñected in response _to deflection
of the movable element, a scale cooperating with
traversed by said beams of light, said movable ele
ment being adapted to deñect through an angle said light source and said mirrors so as to be
traversed bygsaid beams of light, said movable
substantially greater than that required to ad
element being adapted to deflect through an
10 Vance one of the light beams the length of said
scale and one of said mirrors being mounted at
such an angle as to cause a light beam to traverse
said scale during one portion of the angular
movement of said- movable element, the second
15 mirror being mounted at such an angle as to cause
a beam of light to traverse said scale during a
succeeding portion of the angular movement of
said movable element, and ñlters of different col
ors interposed in the paths of said light beams
20 to make their appearances on said scale dis
tinguishable for diiîerent portions of the move
ment of said movable element.
angle substantially greater than that required
to advance one of the light beams the length of 10
the said'scale and one of `said mirrors- being
mounted at such an angle as to cause the light
lbeam to traverse said scale during one portion of
»the angular movement of said movable element,
the second mirror being mounted at such an angle
as to cause the beam of light to traverse said scale
during a succeeding portion of angular move
ment of said movable element.
Без категории
Размер файла
426 Кб
Пожаловаться на содержимое документа