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Патент USA US2111001

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March 15, 1938.
Filed NOV. 15. 1956
M/mv 70/?
B)’ )M. w
Patented Mar. 15, 1938
John Norman, Cicero, 111., assignor to Western
Electric Company, Incorporated, New York,
N. Y., a corporation of New York
Application November 13, 1936, Serial No. 110,703
' 1 Claim.
(Cl. 116-129)
This invention relates to an indicating pointer
for use in electrical measuring instruments, and
more particularly to a balancing mechanism for
such indicating pointers.
struction of weights supported on the arms and
means for adjustably positioning the weights.
The weights are conveniently and economically
formed from a length of wire. The wire is wound
In the operation of electric meters and similar into a helical coil ll having an inside diameter 5
measuring apparatus, it is desirable to maintain slightly larger than the diagonal of the arm so
the moving element of the instrument in accu
that the coil will be supported but freely move
rate static balance and to adjust the balance peri
able on the arm. At the end of the coil the
odically to accommodate variations in character
wire is formed into a loop !8 terminating in a
10 istics and service.
straight end portion 49 which normally extends 10
An object of this invention is to provide im
within the ‘coil periphery as shown by the dotted
proved and readily adjustable apparatus for bal
line in Fig. 4.
ancing the moving element in electrical measur
When the weight is placed on the arm the
ing instruments.
straight end portion is distorted from its normal
In accordance with one embodiment of the in
position and held resiliently against the arm sur- 15
vention an electricalmeter is provided with a face. The weights are preferably made of bronze
balancing mechanism comprising a series of trans
or other non-magnetic composition wire usually
versely ?uted arms extending from the moving used for springs and the loop is formed to impart
element of the meter, and a plurality of weights the desired resiliency to the straight portion.
supported on the arms, the weights comprising‘
In order to position the weight accuratelyand 20
helical springs each having a loop formed in one securely, a series of equally spaced parallel ?utes
end thereof for resiliently engaging‘ a selective or serrations 2d are out in one surface of the arm
?ute in the arm.
for engaging and holding the straight end por
A complete understanding of the invention may tion. The ?utes or grooves extend, for approxi
25 be had by reference to the following detailed de
mately the full length of the arm, permitting the 25
scription and the accompanying drawing, in weight to be anchored at any desired position
along the arm. For some applications the resil~
Fig. 1 is .a plan view of a meter pointer pro— iency in the loop will retain the weight on the
vided with a balancing mechanism embodying arm without the grooves, but their use increases
30 the invention;
the security of the balance setting during move- 30
Fig. 2 is a side view of the apparatus shown in merit of the pointer, and, as they are spaced uni
Fig. 1;
vformly, they facilitate location of the weights at
Fig. 3 is an enlarged fragmentary view of one measured intervals.
arm ofthe apparatus shown in Fig. 1, and
For adjustment of balance the weights are read
Fig. 4 is an end view of the apparatus shown ily shifted by lifting the straight end of the loop 3..
in Fig. 3.
free of the flutes and sliding the weight along the
Referring now to the drawing, an elongated arm to a new position, as established by another
formed pointer or indicating needle it, of the type groove. For accessibility the grooves are located
generally used in electric meters is supportedon in the front faces of the arms.
a balancing cross H which is secured to an actu
ating element (not shown).
The balancing cross
has a body with a central aperture ii for engag
ing a bearing (not shown) on which the assembly
is pivoted and four equally spaced arms extend~
45 ing from the body in one plane. One of the arms
l3 extends vertically upward for supporting the
pointer which is riveted or otherwise secured
thereto. A lower vertical arm it and two opposed
horizontal arms i5 and iii are equal in length and
are preferably rectangular in section. The point
er may be made of aluminum or other light ma
terial and the cross formed of brass or other easily
machineable metal.
This general type of balancing arm is well
55 known and the invention is directed to the con
In cases where the characteristics of the instru- 40
merit will not permit a su?iciently re?ned bal
ance adjustment with weights positioned in one
series of ?utes, a supplementary series is cut in
another side of the arm in staggered relation to
the ?rst series to permit location of the weight 45
at intermediate positions.
The weights are readily made to a predeter
mined value by careful selection of the wire from
which the weight is formed. For convenience, a
slightly excess length of wire is used and the 50
weight is calibrated to ?nal value by cutting sec
tions from the end of the coil.
Although a speci?c structure suitable for a par
ticular application has been described, it is to be
understood that otheradaptations are feasible 55
and that the invention is limited only by the
scope of the following claim.
What is claimed is:
In an indicating pointer for use in electrical
n easuring instruments, a central body portion
f ‘r mounting the pointer in the electrical instru
ent, four equally spaced arms extending radi
ally from the body portion, three of said arms
each having a rectangular cross section and a
10 series of transverse parallel ?utes in the arm
surface, an elongated indicating member secured
to the fourth arm, and individual balancing
weights supported on the ?uted arms, each weight
comprising a helical coil having an inside diam
eter larger than the diagonal of the arm for en
circling the arm and an enlarged loop at one
end of the coil terminating in an elongated
straight portion for resiliently engaging one of
the ?utes to position the weight.
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