Patented Sept. 4, 1951 |
2,566,835 |
UNITED STATES PATENT OFFICE
2,566,835
LOCKING DEVICE
Curt Herzstark, Mauren, Liechtenstein, assignor
to Contina Bureaux- und Rechenmaschinen-
fabrik Aktiengesellschaft, Mauren, Liechtenstein
Application April 27, 1950, Serial No. 158,428
7 Claims. (Cl. 235-144)
The present invention relates to locking devices,
and more particularly to a locking device
for selectively preventing rotation of a first member
and longitudinal movement of a second member.
It is well known in the art to provide detents
of various types for preventing the rotation of
a shaft or for selectively preventing the rotation
of one or another of two shafts. The present
invention differs from previously known devices
in that a detent is slidably positioned on a stationary
member and is movable by rotation of
a first member into engagement with a second
member to prevent longitudinal movement of the
latter and movable by longitudinal movement of
the second member to engage the first member
and prevent rotation thereof. One proposed use
of the present invention is particularly described
hereinafter wherein the device is embodied in a
pocket-sized calculating machine having a centrally
mounted rotatable drive element and transmission
members arranged in a circle around said
drive element adapted to actuate a counting
mechanism, the counting mechanism being
adapted to be disengaged from the actuating
means by axial displacement of the counting mechanism carrier.
The invention consists of a selectively and automatically
operable locking device actuated either
by the drive element or by the carrier of the
counting mechanism to lock the counting mechanism
or the drive element respectively against
movement with respect to the stationary body
of the machine. The locking device comprises
a locking element mounted within the machine
body engageable alternately with the drive element
or the carrier of the counting mechanism
in such manner that either the drive element
locks the counting mechanism against lifting
when the counting mechanism is disconnected
or locks the counting mechanism against axial
displacement when the drive element has been
rotated out of a predetermined position.
The objects and advantages of the invention
will be evident upon consideration of the following
description, reference being made therein to
the accompanying drawings, in which:
Figure 1
is a partial longitudinal section on an
enlarged scale of a calculating machine having
the locking device of the present invention embodied therein.
Figure 2,
a longitudinal section of the locking
device,
Figure 3, a cross sectional
view on the line III-III of Figure 2.
Figure 4, a longitudinal
section of the locking device, in which the various elements of the
device are shown in positions different from those
of Figure 2.
Figure 5, a cross sectional
view on the line V-V of Figure 4, and,
Figure 6, a partial
sectional view on an enlarged scale of a second embodiment of the invention.
The driving member of the miniature calculating
machine of the present invention consists
of an echelon drum 1 which is fixedly mounted
upon a drive shaft 2, to one end of which is secured an operating crank
3. A decade counter
drum 4, having an elongated hub 5, is rotatably
mounted on the shaft 2 and is connected by a
pin 6 with the echelon drum 1 so as to rotate
with the latter. The shaft 2 is mounted, with
the hub 5 of the decade counter drum 4, in the
sleeve 7 which forms a part of the body member
or machine body 8. A counter mechanism sleeve
9 is rotatably mounted upon the sleeve 7, and
is capable of relative axial movement with respect
thereto. The sleeve 9 is connected with
a counter mechanism body 10 by means of a nut
11 which confines a portion of the body 10 between
a shoulder on the sleeve 9 and the nut.
The counter mechanism body consists of a radial
flange and an annular ring which forms a skirt
or the like overlying the external surface of
the cylindrical body 8. Within the counter
mechanism body 10, a plurality of numbering
rollers 12 are arranged in a circle about the
axis of the body. The rollers 12 are mounted
upon shafts 14, upon which are also mounted the
transmission gears 13 for actuating the rollers
12. The transmission gears 13 are arranged to
normally engage with crown gears 15 which
are mounted on shafts 16, the shafts 16 being
actuated, through means not illustrated, by the
echelon drum 1.
In the embodiment of the invention illustrated
in Figures 1 to 5, the body sleeve 7 is provided
with a radial bore 18 within which a locking
element or ball 21 is positioned. The ball 21 and
bore 18 are of such relative size that the ball
protrudes from the bore on both sides of the
sleeve 7 when positioned centrally within the
bore and can be moved only along the axis of
the bore. The hub 5 is provided with a conical
bore 17 which coincides with the bore 18 when
the hub 5 is in a predetermined position of rotation.
Opposite the outer end of the hole 18
and coincident therewith the counter mechanism
sleeve 9 is provided with an annular groove
19 having an inclined lower wall 20. The ball
21 is of such size as to be received within either
of the chambers formed by the bore 18 and conical
bore 17, or the bore 18 and annular groove 19.
The bores 17 and 18 are so positioned in the
relative members as to be directly opposite each
other when the counter mechanism is in operative
position and when the crank 3 is in its normal
position. In this position the crank 3 may
be rotated or the counter mechanism 10 may be
moved axially with respect to the body 8. Upward
movement of the counter mechanism 10 is
manually effected against the action of spring 22,
to move the transmission gears 13 out of engagement
with the crown gears 15. During this axial
displacement of the counting mechanism the
annular groove 19 is moved from the position
shown in Figure 1 into the position
shown in Figure 2,
the result being that the locking ball 21
is moved by the action of the inclined wall 20
into the bore 17, whereafter the outer end of the
bore 18 is blocked by the inner wall of the counter
mechanism sleeve 9. In this position the ball
21 is confined between the conical surface of the bore
17 and the inner wall of the sleeve 9, and,
having engagement in the bore 17 and in the bore
18, locks the hub 5 with respect to the sleeve 7
so that the counter drum 4, echelon drum 1,
shaft 2 and crank 3 are held against rotation.
When the counter mechanism 10 is returned
to its normal position by the spring 22 the hub 5
may be rotated by means of the crank 3. Rotation
of the hub 5 causes movement of the ball
21 into the annular groove 19, by virtue of the
inclined conical walls of the bore 17. The inner
end of the bore 18 will be blocked by the outer
wall of the hub 5. In this position, as shown in
Figure 4, the ball 21
engages in the bore 18 and
groove 19, thus preventing axial movement of
the counter mechanism 10 while allowing rotation thereof.
The locking device according to the second
embodiment of the present invention consists of
an axially slidable locking pin 23 mounted within
a bore in the machine body 8. This locking pin
23 is urged outwardly into engagement with the
covering 25 by a spring 24. The inner circumferential
wall of the covering 25 of the body of
the counter mechanism is provided with an annular
groove 26, having an inclined lower wall 27.
The head 23' of the locking pin 23 engages the
wall 27 in the cover 25. A locking recess 28 is
provided opposite the locking pin 23 in the decade
counter drum 4, or in another member which is
coupled with the drive element 1. If the counting
mechanism is raised, when the operating
crank 3 is in its normal position, the reduced
inner end of the locking pin 23 will be moved by
means of the inclined wall 27 into engagement
with the locking recess 28 to lock the drive element
against rotation with respect to the body 8.
The movement of the cover 25 is limited to such
an extent that it can never be moved above and
beyond the head 23' of the locking pin 23.
When the operating crank 3 is rotated away
from its normal position so that the recess 28
does not coincide with the pin 23, the counting
mechanism cannot be lifted for the reason that
the locking pin 23 is engaged in the annular
groove 26 in the circumference of the counting mechanism.
It is clear from the foregoing description that
I have provided a novel locking device which is
selectively operative to prevent rotation of a first
member and longitudinal movement of a second
member, provision being made to allow rotation
of said longitudinally movable member whether
said member is locked against longitudinal movement
or not. The locking device has a particular
use in the calculating machine described hereinbefore,
but it is clear that such device can be used
wherever the features it provides are desired.
Having described only one preferred embodiment
of my invention, it being clear that various
modifications and departures from the particular
embodiment can be made without departing
from the spirit or scope of my invention, I do
not desire to define my invention by the preceding
description but rather by the appended claims.
What I claim is:
1. A locking device for the operating crank of
a miniature calculating machine having a centrally
arranged rotatable drive element and circularly
arranged transmission members which
are adapted to be disconnected from the drive
element by axial displacement, comprising a body
member, and a locking element movably mounted
in said body member, said locking element being
selectively influenced by said drive element and
said transmission members, said locking element
being influenced upon disconnection of said
transmission members to lock said drive element
against rotation with respect to said body member
and being influenced by said drive element to
prevent disconnection of said transmission members
when said drive element has been moved
away from a predetermined position.
2. A locking device according to
claim 1, including a sleeve, said transmission members
being mounted on said sleeve, a bearing sleeve on said
body member, said transmission member sleeve
being mounted on said bearing sleeve and being
axially movable with respect thereto, said drive
element being rotatably mounted in said bearing
sleeve, said bearing sleeve having a radial bore
through the wall thereof, said drive element having
a radial bore coinciding with said bore in said
bearing sleeve in one position of rotation of said
drive element, said transmission member sleeve
having an annular groove in the inner wall thereof
coinciding with said bore in said bearing
sleeve in one position of axial movement of said
transmission member sleeve, said locking element
being positioned in said bore in said bearing
sleeve and being movable selectively into said
bore in said drive element and into said groove
in said transmission member sleeve.
3. A locking device according to claim 2, in
which said bore in said drive element and said
groove in said transmission member sleeve are
provided with inclined walls, said inclined walls
serving as cam surfaces for moving said locking element.
4. In a calculating machine having a body
member, a drive element rotatably mounted in
said body member, and a counting mechanism
telescopically mounted on said body member for
axial movement with respect to said body member
and said shaft; a locking device, comprising
a locking element slidably mounted on said body
member and arranged to selectively engage said
drive element and said counting mechanism while
maintaining engagement with said body member,
said locking device being influenced by rotation
of said drive element to engage said counting
mechanism and prevent axial movement thereof
and being influenced by axial movement of said
mounting mechanism to engage said drive element
and prevent rotation thereof.
5. In a calculating machine, a locking device
according to claim 4, in which said body member
is provided with a bore, said drive element is
provided with a recess coinciding with said bore
when said drive element is in a predetermined
position with respect to said body member, and
said counting mechanism is provided with a
groove coinciding with said bore when said
counting mechanism is in a predetermined position
with respect to said body member, said locking
element being positioned within said bore,
said locking element being moved into said groove
when said drive element is rotated away from its
said predetermined position to prevent axial
movement of said counting mechanism, said locking
element being moved by said counting mechanism
into said recess when said drive element
is in its predetermined position by axial movement
of said counting mechanism away from its
predetermined position to prevent rotation of said
drive element.
6. In a calculating machine, a locking device
according to claim 5, in which said locking element
is a ball loosely positioned within said bore
so as to be engaged by said drive element and
said counting mechanism.
7. In a calculating machine, a locking device
according to claim 5, in which said locking element
is an elongated pin, including a spring associated
with said pin and urging same into engagement
with said counting mechanism.
CURT HERZSTARK.
REFERENCES CITED
The following references are of record in the file of this
patent:
| UNITED STATES PATENTS |
|
| Number | | Name |
| Date |
 1,400,679 | Jensen (1) | Dec. 20, 1921 |
| 1,414,716 | Trosien (2) | May 2, 1922 |
|
| FOREIGN PATENTS |
| Number | | Country |
| Date |
| 535,478 | Great Britain | Apr. 10, 1941 |
Figures 1,
2,
3,
4,
5,
6,
all.
Notes:
- According to the CURTA Service Manuals from 1967, type I used
a locking mechanism with a ball, as described in the first embodiment.
Type II also used the first embodiment, but with a (vertical) locking pin
instead of a ball. Pins in various lengths were available to tune the
axial movement of the counter mechanism 10. (back)
- Obviously a typo in the original: read "counting". (back)
- This CURTA Patent was HTML'ized by
Andries de Man from a microfilm copy.
- See also US Patents 2,525,352;
2,533,372;
2,544,426;
and German Patents 747073 and 747074.
- For more information, see Rick Furr's CURTA Calculator page.
Andries de Man 5/15/1997
