1. No category

Aug- 22, 1933-
o. c. BLOMGREN
1,923,416
ARMATURE TURNING AND UNDERCUTTING‘ LATHE
Filed Nov. 27, 1931
3 Sheets-Shegt l
20
29
290 ~
16
19
12/
07/
Aug- 22, 1933-
0. c. BLOMGREN
1,923,416
ARMATURE TURNING AND UNDERCUTTING LATHE
[Filed Nov. 27, 1931
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s Sheets-Sheet 2
Aug. 22, 1933.
,
Q Q BLQMGREN
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1,923,416
ARMATURE TURNING AND UNDERCUTTING LATHE
Filed Nov. 27, 1931
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1,923,416
Patented Aug. 22, 1933
UNITED STATES PATENT OFFICE
1,923,416
ARMATUKE TURNING AND UNDERCUTTING
LATHE
Oscar C.‘Bl0mgren, Winnetka, 111.
Application November 27, 1931
Serial No. 577,425
14 Claims.
(Cl. 29-27)
Fig. 2 is a horizontal section takensubstantially
My invention relates to armature condition
on
line 2-2 of Fig. 1;
ing tools and has to do more particularly with
Fig. 3 is an enlarged sectional view taken sub
lathe structure for turning. and undercutting
stantially in the same position as Fig. 2 but show
commutators.
64),
One of the objects of my invention is to provide ing the tool in position for undercutting;
CI:
Fig.
41
is
a
separated
top
plan
view
of
the
motor
a novel form of lathe structure for the above pur
poses. which isv adapted to support the armature driven chuck structure shown in Fig. 1;
Fig. 5 is a partial elevational view of another
for rotational movement preferably in vertical or
upwardly-directed position upon a center-sup adaptation of the structureshown in Fig. 1 and
illustrating a modi?ed form of. motor-driven 65,
10 port thereby providing a better. balanced and
smoother operating. structure and insuring a bet chuck structure;
ter and more uniform ?nish in» the. armature
Fig. 6 is a section taken substantially on line
6-6 of Fig. 5;
dressing operation.
.
Fig. '7 is an enlarged vertical sectional view of
Another object is to’ provide an inexpensive
the
motor-driven chuck structure of Fig. 5;v and, 71).
structure of the foregoing character which is of
Fig. 8 is a section taken substantially on line
compact form‘, easily handled and adjusted and
8-—8 of. Fig. '7.
which is well adapted for small garage service.
Referring particularly to. the arrangement of
In automotive, and related, service work, one
may be called upon to dress. the commutators of Fig. 1, the tool illustrated comprises a base 10
These ?xedly supporting an upright standardll which.- 75
armatures may vary as to- shaft diameters, shaft is, preferably, of rectangular shape in cross‘ sec
lengths, the provision of suitable shaft “centers", tion. This standard 11 slidably supports a tele
and the like- In tools heretofore employed for scoping support casing 12 of similar shape in
several different types of armatures.
dressing armatures considerable inconvenience cross section to prevent rotation of the same
4 has, therefore, been experienced due to these dif relative to the standard 11. The casing 12 is
held in a plurality of predetermined, vertically
ferences. Such variations, in the use of prior
structures, make it quite expensive for one to adjusted positions upon the standard 11 by a
properly equip for armature service work due to plurality of set screws 13 carried by the casing
the necessity of acquiring adapter accessories in 12, the pointed ends 13a of which are adapted
order to be in position to dress all kinds of arma to seat in V-shaped sockets 11a in the standard
tures. A further object of my invention is to pro 11. The upper'end of the support member 12 is
vide novel chuck structure which has universal reduced in size as at 14 and is extended inwardly
adaptability to various diameter and length at right angles, and in a direction parallel with
the base 10, providing a center-support arm 15.
armature shafts regardless whether the same are
' provided with. the usual. “centers”, whereby one The end of arm 15 terminates in a chuck ring 16,
tool may well serve for the dressing of substan the center of the bore of which is “on center”
with respect to the work as will be seen herein
tially all types of armatures.
Additional objects are to provide a tool which
may be readily and quickly adjusted for both
turning and undercutting operations, a common
cutter device being employed for this purpose; to
provide a tool which requires a minimum of skill
to- operate and which is of such durability as to
render efficient service over a long period of time;
45 and to provide a portable type of tool which may
be readily and easily moved by the operator from
after. The bore of the chuck ring 16 is threaded
to receive'a threaded center stem 19 which is
adapted to be locked in adjusted position by nut
20. The armature structure, illustrated at 21,
9.5
may be provided with a shaft, the ends 22a and
22b of which may be respectively supported “on
center” by the center stem 19 and the motor
chuck 18. The base 10, at a point laterally 1
spaced from the standard 11, supports a vertical
place to place to facilitate armature-dressing motor 17, the vertical drive shaft (not shown in
operations.
.
Other objects and advantages will become ap
50 parent as this description progresses and by ref
erence to the drawings in which,—
Figure 1 is an elevational View, partially in sec
tion, of. one form of lathe structure embodying my
detail) of which supports the universal chuck
structure 18 “on center” with respect to the chuck‘ lor0
ring 16 and the work.
»
The expense heretofore necessary to properly
equip an automotive service garage for servicing
of the various kinds of automotive-used, and the
as hereinabove ex
invention and illustrating an armature in position like, armatures on the market,
plained, has been such as to practically prohibit 11,0 I
to be dressed;
2
1,923,416
the use of tools of this character in the smaller
garage service work. My invention provides a
tool which is inexpensive and is universally ap~
plicable to practically all known armature
structures which one may be called upon to serv
ice in automotive repair work; thereby placing
armature dressing operations: within the service
limits of even the smaller service garages.
To
this end, one of the important features of my
10 invention is the provision of chuck means which
is universally adaptable to a wide range of arma
ture structures, regardless of the above-men
tioned variations therein.
Speci?cally, the chuck structure 18 which is
15 connected to and driven by the motor shaft, takes
the form of a member (Figs 1 and 4) having an
maintain the shaft centered upon its lower center
support for the turning movement of the arma
ture. This centering arrangement is not lim
ited to use in conjunction with the motor chuck
structure shown in Fig. 5, but may be used equally 80
well with the arrangement shown in Fig. 1, or
otherwise.
The turning and undercutting operations are
accomplished by means of a single knife or cutter
device 30 supported and operated in the following 85
manner: A rectangularly-shaped collar 31 is slid
ably mounted on the upper end of the support
member 12 and it is provided with an arm 32 ex
tending in lateral direction parallel with the
base 10 and at right angles to the support 12.
arm 32 supports another arm 33 which is
inverted cone-shaped socket 181, the tapering This
provided with a longitudinal slot 33a receiving
wall of which is provided with a plurality (pref~
the stem of a screw 34 carried by the arm 32.
erably three) of outwardly projecting and rela
With this arrangement, the arm 33 which carries
20 tively sharp-edged ribs 23.
This chuck socket is
adapted to wedgingly receive the lower end 22*’
of the armature shaft and, due to the weight of
the armature and the relative sharp edge of the
ribs 23, the shaft 221‘ is grippingly engaged and
25 the armature is rotated with its axis in vertical
position as the motor shaft rotates. This chuck
structure, with the armature vshaft end
en“
gaged “on center” with the pointed end of the
. center stem 19, insures self-adjustment of the
30 armature shaft end 22b to an “on center” posi
tion as will be readily appreciated.
The ?aring shape of the chuck socket l8a pro
vides for the reception of armature shaft ends
,of different diameters. In the event that the
armature shaft may be of a diameter which will
not permit entry of the same within the chuck
socket 18%, I may employ the motor-driven chuck
structure illustrated in Figs. 5, 7 and 8.
Speci?~
the cutter 30 may be adjusted to the desired ex—
95
tent toward and from the armature by merely
loosening the screw 34 and moving the arm 33 rel
ative to the arm 32. The screw 34 when tight
ened holds these two arms in their predetermined
adjusted position. The arm 33 is provided with 100
a thickened head 35 having a rectangularly
shaped opening therethrough for receiving the
similarly-shaped body of the cutter 30, which
opening is projected at an angle to the longitu
dinal center line of the arm 33 and toward the 105
work. The cutter is adjustable in its support
35 and is held in adjusted position by a set screw
36. Furthermore, the cutter is provided at one
end with a turning edge 30a and at the other end
with an undercutting edge 30'), these cutting edges ‘110
being, preferably,of the shape best illustrated in
Figs. 2 and 3.
As will be understood, for best
operation of the dressed armature, after the turn
ing of the commutator, the mica or other insulat
40 ing its lower body portion tapered complemental
ly to the taper of the chuck socket 182‘ and hav ing material between the commutator segments 115
ing longitudinal grooves 24:1 which align with 38 should be undercut; and it has been found
and receive the chuck socket ribs 23 for holding from practical demonstration that best under
cutting results are accomplished by arranging the
. . the center head 24 against rotation. The
. cally, I provide a removable center head 24 hav
upper
45v body portion ‘24b of this center head is cone
shaped and pointed to engage in the center open
ing 25 in the enlarged shaft end 22°. To effect
a positive drive between the chuck structure 18
and the shaft end 22°, I provide a suitable form of
50 lathe connection or dog 26 having
collar por
cutting edge 30b so that it provides a V-shaped
groove in the mica 37 between the commutator
segments 38 with the apex of the V spaced sub
stantially equal distances from the adjacent
edges of the commutator segments (Fig. 3).
In the operation of the foregoing structure,
tion 26a secured to the shaft end 220 by a lock for turning of the commutator 39, the motor is 125
screw 27 and a depending shank 261“ which en~
gages a laterally-extending pin 28 carried by the
c , chuck 18.
Obviously, as the motor shaft rotates,
5s rotating the chuck 18, the armature 21 is rotated.
Adjustment of the casing support 12 and the
center stem 19 will accommodate armature shafts
of different lengths within predetermined limits.
However, such shaft-length limits may be ex
60 ceeded and, in that case, as illustrated in Fig. 5,
the lengthened end 22d (Fig. 5) of the shaft is
supported as follows: The chuck collar 16 is
provided with a plurality (preferably three)‘ an
. nularly arranged, equally spaced center-support
65' screws 29 which are manually and independently
adjustable as will be obvious from Figs. 5 and 6.
In operation, the armature 21 is mounted in posi
tion upon the motor chuck with its shaft end 22d
set in operation to rotate the armature structure.
The cutter 30, having been properly adjusted with
its edge 30E projected toward the commutator, is
then moved up and down in engagement with the
commutator, accomplishing the turning opera 130
tion to the desired extent. When undercutting,
the cutter edges are reversed, the edge 302L pro~
jecting toward the work. The armature is
turned to a position wherein the edge 30b of the
cutter engages between the commutator segments 135
and, the armature remaining stationary, the
knife is moved vertically to make the cut.
Al
though I use a single, double-edge cutter inthe
preferred form, separate cutters with the proper
single edges may be employed for turning and 140
undercutting operations without departing from
my invention. The movement of the cutter in
projecting upwardly through the opening in the both of these instances is accomplished by means
70 collar 16, and the screws 29 are adjusted to similar of suitable handle and operating connections.
extents into engagement with the shaft end 22d Speci?cally, I may employ a handle 40 pivotally
supporting the same ,“on center” for rotative supported at 41 by a rectangularly-shaped collar
movement. The screws 29 are set up in such a 42 secured in adjusted position upon the support
. manner as to permit the free rotation of the casing 12 by set screw 43. This collar 42 is ad-.
armature 21 but their relationship is such as to justable vertically upon the support ‘12 and serves i
as a limiting stop for the knife-carrying, slid
3
1,923,415
atively connected to saidcarrier for reciprocat
vable collar 31. In this manner, the lowermost
cutter vertically.
position of the cutter is predetermined so that ing4. said
In a'tool of the class described, the combina
the cutter may be moved over and longitudinally ‘
along only a predetermined surface .to be cut. tion of a base, a standard carried thereby, a
rotatable armature support carried by said base
This is, of course, desirable to avoid injury to the and having its axis of rotation projecting sub
armature part not to be dressed. - The handle 40 stantially parallel with said standard, an arm
pivotally supports, as at 44, a link 45 which is, projecting laterally from and at substantially
in turn, pivotally connected, as at 46, to the collar right angles to said standard, armature center
“ 10
31. The relationship ofthe pivots 41, 44, and ing and rotation-guide means carried by said 85
46 is such that by grasping the outer end of the
:in alignment with said rotatable armature
handle 40 and moving the same up and down, the arm
support, a cutter carrier supported by said stand
collar 31 and cutter 30 are readily and easily
moved up and down along the support 12. The
downward movement of the-handle 40 is yield
ingly opposed by a spring 47 connected at one end
15 to the collar 31 and at the other‘end to the handle
‘pivot 44. This spring, also, tends to return the
collar 31 ‘and cutter 30 to their uppermost posi~
:ard for slide movement thereon, a cutter ad
20 my invention is well adapted to the accomplish
5. In structure of the class described, a port
able, self-contained unit comprising a base, a
justably supported by said vcarrier, means for ad
justing said carrier within itself for projecting
said cutter relative to the armature, and means
including reciprocation-limiting stop means sup
ported by said standard and operatively con
nected to said carrier for reciprocating said
tions (Fig. 1).
‘
;
.
From the foregoing, it will be appreciated that cutter relative to the armature.
ment of the objects hereinabove stated. Itwill
be understood that while I have shown several
adaptations of my invention, other changes in
details and arrangements of parts may be made
without departing from the spirit and scope of
vertically-projecting standard carried by said
base, a motor carried by said base and having a
my invention as de?ned by the ‘claims which
follow.
I claim:
.
1. In structure of the class described, the com
a base, an upwardly-projecting
standard carried by said base, a rotatable chuck
30 bination of
structure supported by said base with its axis of
:rotation projected in upward direction substan
tially parallel with said standard, means for ro
35 tating said chuck structure, a support member
mounted on said standard for longitudinal ad
.justment relative thereto and having a laterally
extending arm, ‘a centering and supporting de~
vice carried by said arm in alignment with the
40
axis of said chuck structure, and a cutter ad
vertically-projecting drive shaft, means carried 100
by said drive shaft for centering and supporting
one end of the armature shaft, a vertically-ad‘
justable support member carried by said stand
ard ‘and having a lateral arm, means carried by
said arm adapted for centering and supporting 105
the other end of said armature shaft, and a
cutter supported by said support member for
sliding movement relative thereto and to the
armature to be dressed.
‘
r
6. In structure of the class described, a base,
a standard supported thereby, an arm supported
no
by said standard, a chuck supported by said
base and rotatable about an axis substantially
parallel with said standard and adapted to ac
commodate support and center a plurality of 115
diflerent—size armature shafts, means for rotat
ing said chuck, and a support immovably car
justable longitudinally of the armature being ried by said arm and adjustable within itself to
dressed.
accommodate different size armature shafts, said ,
2. In structure of the class described, a port
stationary support having provision for secure
45 able, self-contained unit comprising a base, an ment therein of removable shaft centering
upwardly-extending standard supported by said
base, a laterally-extending arm supported by said means.
'7. In structure of the class described, a base,
standard, an armature centering structure sup
a vertical standard supported thereby, a sub
ported by said arm, rotatable armature center stantially horizontal arm supported by said
ing and supporting structure supported by said standard, a chuck supported by said base and ro
base with the axis of such structure projected tatable about a vertical axis and shaped to re
in upward direction in alignment with the axis ceive a plurality of different-size armature shafts
of said armature centering structure, means for for supporting and centering the armature,
rotating said armature centering and supporting means for rotating said chuck, a ring-shaped ‘130
structure with the latter supporting a substantial member carried by said arm with its axis on cen
part of the weight of the armature, a cutter ter with respect to the axis of said rotatable chuck,
supported by said standard for longitudinal re
and a centering stem carried by said ring member
ciprocation relative to the armature, and means and adapted to engage the adjacent armature .
. for reciprocating said cutter.
3. In a tool of the class described, the com
bination of a base, a standard carried thereby
shaft end on center.
8. In structure of the class described, a base, a
standard supported thereby, an arm supported by
and projecting vertically therefrom, a rotatable said standard, a rotatable chuck adapted to ac,
armature support carried by said base and hav
commodate a plurality of different-size armature
ing its axis of rotation projecting in vertical shafts for supporting and centering the armature, 140
direction
substantially
parallel
with
said
stand
.65
means for rotating said chuck, a ring-shaped
ard, an arm projecting laterally from and at
substantially right angles to said standard, arma~ member carried by said arm with its axis on cen
ter with respect to the axis of said rotatable
ture centering and rotation-guide means car
ried by said arm in alignment with said rotatable chuck, and elements carried by said ring-shaped
armature support, a cutter carrier supported by member and adjustable toward and from the cen
ter thereof for supporting and centering the ad
said standard for vertical slide movement, a
cutter adjustably supported by said carrier,
means for adjusting said carrier within itself for
. projecting said cutter relative to the armature,
and means supported by said standard and oper
jacent end of the armature shaft projected
through said ring-shaped member.
9. In structure of the class described, a base,
a standard supported thereby, an arm supported
4
1,923,416
by said standard, a rotatable chuck adapted to
accommodate a plurality of different-size arma—
ture shafts for supporting and centering the ar
mature, means for rotating said chuck, a ring
member carried by said arm with its axis on cen
ter with respect to the axis of said rotatable
chuck, and a plurality of equally-spaced, radial
axis which comprises a member having an in
verted cone-shaped socket, the axis of which is
disposed in vertical direction to receive one end
of a vertically-disposed armature shaft, said
socket having spaced, longitudinally-extending 80
ribs around its wall against which the end of
ly disposed screw members carried by said ring the armature shaft seats, drive-engagement be
member and adjustable toward the center of said tween the armature shaft and said ribs being
effected through the pressure imposed by the
ring member to engage and center and support weight
of the armature.
85
the adjacent end of the armature shaft for ro
13. In structure of the class described, means
tation of the armature.
10. In structure of the class described, means for supporting and centering the armature in
for supporting and centering the armature in position for rotation about a vertical axis which
position for rotation which comprises a socket comprises a member having an inverted cone
member in which the lower end of the armature shaped socket, ribs extending longitudinally
shaft is received, means associated with said along the wall of said socket, and a center-sup
socket for grippingly engaging one end of the port device having one end of its body portion
20
2.5,
armature shaft for rotational movement thereof, shaped complementally to said socket and
grooved to receive said ribs, and having its other
end portion pointed and adapted to project be 95
means for rotating said lower socket member, an
upper and vertically spaced center stem sup
ported with its axis on center with respect to the
axis of said socket member, and means for ad
justing said stem to engage one of its ends on cen
ter with the upper end of the armature shaft.
11. In structure of the class described, means
for supporting and centering the armature in
position for rotation which comprises a socket
member
in which one end of the armature shaft
30
is received, means associated with said socket
for grippingly engaging said one end of the ar
mature shaft for rotational movement thereof, a
yond said socket to engage the end of the arma
ture shaft, means for interlocking said socket
member and armature shaft for rotation together, and means for rotating said socket mem
ber.
100
14. In a tool of the class described, a base, a
standard carried thereby, a chuck structure ro
tatable about an upwardly-directed axis and
adapted to bear the weight of the armature, and
means for rotating said chuck structure and 105
armature, a support member mounted upon said
second stationary socket member having its axis standard for longitudinal adjustment relative
thereto, a stationary centering device carried
35 on center with respect to said first socket mem
by
said member in alignment with said chuck
ber, and. means associated with said second socket
member adapted to engage and hold the other end structure and adapted to engage the armature 110
of the armature shaft centered while the arma shaft, a cutter supported by said member for
reciprocation and for adjustment toward and
ture is in rotation.
from
the armature, and means supported by said
12. In structure of the class described, means
40
for supporting and centering the armature in member for reciprocating said cutter.
115
position for rotation about an upwardly-directed
OSCAR C. BLOMGREN.
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