U.S. patent number 3,903,686 [Application Number 05/486,617] was granted by the patent office on 1975-09-09 for chronograph movement.
This patent grant is currently assigned to Societe Suisse pour l'Industrie Horlogere Management. Invention is credited to Hughes Burki.
United States Patent |
3,903,686 |
Burki |
September 9, 1975 |
Chronograph movement
Abstract
A conventional timepiece movement with a seconds hand, minutes
hand and hour hand combined with a chronograph movement including a
minutes counter and hours counter and having the capability to
zeroize the seconds hand, minutes counter and hours counter.
Inventors: |
Burki; Hughes (Vaud,
CH) |
Assignee: |
Societe Suisse pour l'Industrie
Horlogere Management (Bern, CH)
|
Family
ID: |
4358622 |
Appl.
No.: |
05/486,617 |
Filed: |
July 8, 1974 |
Foreign Application Priority Data
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|
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Jul 10, 1973 [CH] |
|
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10034/73 |
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Current U.S.
Class: |
368/106;
968/835 |
Current CPC
Class: |
G04F
7/0823 (20130101); G04F 7/0833 (20130101) |
Current International
Class: |
G04F
7/00 (20060101); G04F 7/08 (20060101); G04f
007/04 () |
Field of
Search: |
;58/74-79 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Miller, Jr.; George H.
Attorney, Agent or Firm: Stevens, Davis, Miller &
Mosher
Claims
What is claimed is:
1. A chronograph movement comprising an hour-wheel and a
minute-wheel continuously driven by a gear-train, and further
comprising a chronograph-pinion and a minute-counter, each adapted
to be stopped, returned to zero, or connected to said gear-train
and driven, wherein said chronograph-pinion and said minute-counter
each have toothings countinuously engaged with corresponding
toothings of a wheel-and-pinion constituting the driven part of a
friction clutch, and the driving part of said clutch is a
wheel-and-pinion of said gear-train.
2. A chronograph movement in accordance with claim 1, wherein said
minute-counter and said chronograph-pinion are coaxial with said
hour-wheel and said minute-wheel.
3. A chronograph movement in accordance with claim 1, wherein said
driving part and said driven part are coaxial.
4. A chronograph movement in accordance with claim 3, wherein said
driving part comprises a pinion-toothing engaged with a center
wheel-and-pinion and a wheel-toothing engaged with a fourth wheel
pinion, said fourth wheel pinion and said center wheel-and-pinion
constituting elements of other wheels and pinions of said
gear-train.
5. A chronograph movement in accordance with claim 1, wherein said
minute-wheel bears a cannon-pinion bearing a minute-hand, said
minute-wheel being coupled to said cannon-pinion by a friction
coupling.
6. A chronograph movement in accordance with claim 5, wherein said
driving part further comprises a second pinion-toothing engaged
with said minute wheel.
7. A chronograph movement in accordance with claim 5, wherein said
two pinion-toothings of said driving part are of different
diameters, and said center wheel-and-pinion is driven by a driving
barrel at a speed greater than one revolution per hour.
8. A chronograph movement in accordance with claim 5, wherein said
minute-counter comprises a counter-wheel engaged with a
pinion-toothing of said driven part, a pipe engaged on said
cannon-pinion, and a further pinion integral with a pipe of said
minute-counter, said further pinion driving an hour-counter.
9. A chronograph movement in accordance with claim 8, further
comprising a speed-reducing wheel-and-pinion, the wheel of which is
engaged with said further pinion, and the pinion of which is
engaged with a wheel of a wheel-and-pinion constituting said
hour-counter.
10. A chronograph movement in accordance with claim 9, wherein said
wheel of said hour-counter is friction-coupled to an arbor bearing
an hour-counter hand.
Description
This invention relates to a chronograph movement comprising an
hour-wheel and a minute-wheel continuously driven by a gear-train,
and further comprising a chronograph-pinion and a minute-counter,
each adapted to be stopped, returned to zero, or connected to the
gear-train and driven.
Most of the known chronograph movements comprise the usual wheels
and pinions of a watch movement and, in addition, a
chronograph-arbor integral with a chronograph-wheel and means for
connecting the chronograph-wheel to a fourth wheel-and-pinion,
these means being controllable from the outside so as to cause the
chronograph-hand to start and stop. When the chronograph is
equipped with a minute-counter, the latter is driven from the
chronograph-wheel, either by a finger actuating the counter-wheel
by one step per revolution, or by an oscillating pinion which
produces a continuous slow motion of the counter-hand.
In some of the known chronographs, the minute-counter is coaxial
with the chronograph-hand. It is then connected to the center
wheel-and-pinion by a friction coupling, and the mechanism
comprises a brake which can block the counter when the chronograph
hand is uncoupled.
All of these known mechanisms necessitate one or more levers
bearing wheels intended to produce the drives needed to operate the
chronograph-hand and the counter or counters. In certain cases, the
chronograph-hand is driven via a friction clutch.
It is the object of this invention to provide a chronograph
movement comprising a chronograph-pinion and a minute-counter, but
not requiring either a lever or a brake, and being of simplified
construction.
To this end, in the chronograph movement according to the present
invention of the aforementioned type, the chronograph-pinion and
the minute-counter each have toothings continuously engaged with
corresponding toothings of a wheel-and-pinion constituting the
driven part of a friction clutch, and the driving part of the
clutch is a wheel-and-pinion of the gear-train.
A preferred embodiment of the invention will now be described in
detail with reference to the accompanying drawing, which is a
partial axial section through the chronograph movement.
Only those elements necessary for understanding the particularities
of the chronograph movement described are illustrated. The elements
which are not shown are of conventional design.
The drawing shows part of a base plate 1 of the movement and part
of a wheel-train bridge 2. A chronograph bridge 3 is fastened under
the base plate 1 in such a way that certain elements may pivot, as
will be seen further on. Below the chronograph bridge 3 is a
retaining plate 4, through a central opening 5 of which pass the
various pipes of the members bearing the center hands. The
retaining plate 4 also has an off-center opening 6 through which an
arbor 7 of an hour-counter passes.
The chronograph movement illustrated comprises a mainspring lodged
in a barrel which rotates at a slightly greater speed than usual.
The drum of this barrel drives an off-center center
wheel-and-pinion 8, part of the wheel of which may be seen in the
drawing. The center wheel-and-pinion 8 likewise rotates at a
slightly greater speed than usual, which is one revolution per
hour, and pivots between the wheel-train bridge 3 and the base
plate 1 about an off-center arbor. The wheel of the
wheel-and-pinion 8 engages a pinion-toothing 9 of a third
wheel-and-pinion 10, which is of a special design. The
pinion-toothing 9 is integral with a toothed disc 11 which
represents the wheel-toothing of the third wheel-and-pinion 10, and
it is also integral with an auxiliary pinion-toothing 12 smaller in
diameter than the pinion-toothing 9. As in a conventional movement,
the wheel 11 drives an off-center fourth wheel pinion (not shown)
which transmits the driving torque to an escape wheel actuating the
escapement. The wheel-and-pinion 10 has a cylindrical passage along
its axis, and it is mounted loose on an arbor 13 which pivots at
its upper end in a bearing 14, integral with the bridge 2, and at
its lower end in the bottom 15 of a socket 16 driven into an
opening in the chronograph bridge 3. The sidewall of the socket 16
has a recess in order to enable the driving of the minute-counter,
as will be seen further on.
The third wheel-and-pinion 10 is held in place axially by a
shoulder of the arbor 13 on which the end face of the
pinion-toothing 12 rests, and by a sleeve 17 driven onto the upper
end of the arbor 13. The position of the sleeve 17 determines the
clearance of the wheel-and-pinion 10.
Guided freely about the sleeve 17 is a clutch plate 18 provided
with a peripheral toothing 19. The plate 18 is normally pressed
against the wheel 11 by a resilient element 20 held under tension
between a collar of the sleeve 17 and a circular rim of the plate
18. It can, however, be axially displaced with respect to the arbor
13 by means of a control member (not shown).
The plate 18 is adapted to drive the arbor 13 rotatingly by the
friction of the resilient member or spring 20 on the rim of the
plate 18 and on the sleeve 17, and hence a pinion-toothing 21,
situated at the lower end of the arbor 13 inside the socket 16, is
rotated with the wheel-and-pinion 10 or, on the contrary, blocked,
according to the position of the control member of the plate 18.
Thus the whole assembly constitutes a clutch, the driven part of
which, consisting of the arbor 13 and the plate 18, comprises a
number of toothings of different diameters which are coupled or
uncoupled simultaneously.
The indicators of the chronograph movement described here are so
arranged that they can be started, stopped, and returned to zero
accurately and simply. The indicator members comprise, first of
all, a chronograph-arbor 22, the upper end of which pivots in a
bearing 23 integral with the bridge 2, while the lower end bears a
chronograph-hand 24. The arbor 22 is machined with a
pinion-toothing 25 which is constantly engaged with the toothing 19
of the plate 18. It carries a return-to-zero heartpiece 26 disposed
immediately above the inner face of the base plate 1 and intended
to cooperate with a hammer 26a. Near the lower end of the arbor 22
is a collar 27 which guides it in the inner bore of the pipe of a
cannon-pinion 28. The arbor 22 has a frustoconical shoulder 47
between the toothed portion 25 and the portion of the arbor
immediately adjacent thereto. On this shoulder 47 there rests a
spring 48 consisting of a straight wire borne by a pillar (not
shown) set upright in the base plate 1. The position and height of
this pillar are such that the spring-wire 48 exerts an oblique
force, acting in the direction indicated by an arrow F, upon the
arbor 22. The spring 48 has a number of functions. First of all, it
is a source of friction on the arbor 22. Furthermore, it prevents
any jumping or wavering of the chronograph-hand at the moment of
its starting up, i.e., when the plate 18 moves axially to come into
contact with the plate 11. For this purpose, the hole of the
bearing 23 is given a non-circular shape, slightly elongated in the
direction determined by the parallel axes of the wheel-and-pinion
10 and the arbor 22. The spring 48 exerts upon the arbor 22 a force
of which the horizontal component likewise acts in that direction
and which consequently tends to press the pinion-toothing 25
against the toothing 19 of the plate 18. The profiles of these
toothings will be such that the points of the teeth of the toothing
19 press against the bottoms of the tooth-gaps of the toothing 25
without the upper pivot of the arbor 22 pressing against the flank
of the hole of the bearing 23. The length of this hole will be such
that the short-side nearest the toothing 19 is never in contact
with the upper pivot of the chronograph-arbor 22, while the
opposite short-side offers sufficient play to absorb any
eccentricity of the toothings 25 and 19, but little enough play to
furnish support for the pivot of the chronograph-pinion 25 and thus
to prevent disengagement of the toothings when the
chronograph-pinion 25 is returned to zero.
This function of the spring 48 therefore ensures that the
chronograph-hand will start up without any jerk, besides avoiding
any risk of jamming due to possible eccentricity of the toothing
19.
Moreover, the vertical component of the force F acting in the
direction of the axis of the arbor 22 presses the shoulder at the
base of the upper pivot of the arbor 22 against the bearing 23, and
this ensures the axial position of the arbor 22. It will be noted
that this position is such that there is no risk of the heart-piece
26 coming into contact with the inner face of the base plate 1 and
thereby being braked.
The details of this arrangement for avoiding angular play of the
toothings may be described as follows: in a positioning arrangement
for a rotating part having a toothing engaged with a driving
toothing, the rotating part pivots with play in at least one
bearing and comprises a shoulder against which a resilient element
presses continuously, exerting upon the rotating part a force
having an axial component and a horizontal component, the
horizontal component being directed towards the axis of the driving
toothing.
The cannon-pinion 28 has a toothing 29 extending between the base
plate 1 and the chronograph bridge 3, the pipe of the cannon-pinion
28 passing through a circular opening in the bridge 3. The
cannon-pinion 28 pivots in a hole in the base plate 1 and carries a
friction-mounted minute-wheel 31 on a collar 30 having
frustoconical flanks. The minute-wheel 31 is in continuous
engagement with the pinion-toothing 12 of the third
wheel-and-pinion 10. Thus the wheel 31 is driven at the rate of one
revolution per hour and normally drives the cannon-pinion 28 at
this same speed. The cannon-pinion 28 bears a minute-hand 32. It is
guided at the level of the collar 27 in the end portion of a pipe
33 of the minute-counter which surrounds it, and it pivots in the
opening in the chronograph bridge 3 provided for the passage of the
cannon-pinion 28 and the chronograph-arbor 22. The pipe 33 is
integral with a heart-piece 34 and bears a counter-wheel 35. The
counter-wheel 35 is freely engaged on a cylindrical bearing surface
of the pipe 33. The wheel 35 is of the same diameter as the wheel
31, and it meshes continuously with the toothing 21 of the arbor
13, this toothing 21 being of the same diameter as the toothing
12.
A spring 36 which rests on one face of a pinion 41 driven onto the
pipe 33 positions the wheel 35 axially and produces the friction
necessary to drive the heart-piece 34 and its pipe 33. A washer 37
which rests on the other face of the pinion 41 axially positions an
hour-wheel 38 which extends immediately under the retaining plate
4, and the pipe of which passes through the opening 5 and guides
the pipe 33. Thus under the minute-hand 32 there extends a
minute-counter hand 39, fastened to the end of the pipe 33, and
under this hand 39 there further extends an hour-hand 40, fastened
to the end of the pipe of the wheel 38. The pinion 41 fastened
rigidly on the pipe 33 is integral with the minute-counter and
drives the wheel of a transmission wheel-and-pinion 42 mounted on a
pivot pin 43 set upright in the base plate 1. The pinion-toothing
of this wheel-and-pinion 42 drives a wheel 44 which is mounted on
the arbor 7 in such a way as to be friction-coupled to the arbor 7.
A heartpiece 45 is integral with the arbor 7, as is an hour-counter
hand 46.
In order to establish the connection between the hour-wheel 38 and
the toothing 29 of the cannon-pinion 28, and to enable the hand 40
to indicate the hour, a minute wheel-and-pinion (not shown) is
provided between the base plate 1 and the retaining plate 4. This
wheel-and-pinion will comprise a wheel-toothing engaged with the
toothing 29 of the cannon-pinion 28 and a pinion-toothing engaged
with the hour-wheel 38.
Thus the essential elements of the chronograph movement illustrated
in the drawing have been described, and as may be seen, its
operation derives from the arrangement described, particularly from
that of the third wheel-and-pinion.
When the clutch is uncoupled by axial upward displacement of the
plate 18, the pinion 25 and the wheel 35 are immediately blocked by
the toothings 19 and 21. The wheel-and-pinion 10 continues to be
driven by the center-wheel 8 and drives the wheel 31, the
cannon-pinion 28, and, via the minute wheel-and-pinion, the
hour-wheel 38, i.e., the hour and minute wheels and pinions of the
movement. When pressure is exerted on the push-piece which returns
the chronograph-hand and the counter-hands to zero, one or more
hammers 26a, 34a and 45a act simultaneously upon the heart-pieces
26, 34 and 45 respectively. Due to the rotation of the arbor 22
driven by the heart-piece 26, the clutch-plate 18, which has
remained engaged with the toothing 25 but is no longer in contact
with the wheel-and-pinion 10, rotates against the friction of the
spring 20. The heart-piece 34 causes the pipe 33 to rotate,
returning the hand 39 to zero, but without necessarily driving the
wheel 35, which is friction-fitted, and this facilitates the return
to zero of the heart-piece 34. This rotating movement of the pipe
33 brings about a rotation of the pinion 41 and, consequently, of
the wheel-and-pinion 42 and the wheel 44; but at the same time, the
arbor 7, as well as the hand 46 and the heart-piece 45, rotates so
as to return the hand 46 to zero. It follows that the arbor 7
rotates frictionally in the wheel 44.
To start up the chronograph, it suffices to move the hammer or
hammers away from the heart-pieces 26, 34, and 45 and to release
the plate 18, so that under the effect of the spring 20, it rests
against the upper face of the wheel-and-pinion 10. From that moment
on, the chronograph-hand is driven by the toothing 19, and the
arbor 13 is driven via the spring 20, so that the toothing 21
drives the wheel 35 at the same speed as the wheel 31. The friction
of the wheel 35 on the heart-piece 34, and that of the spring 36 on
the pinion 41, cause the hand 39 of the minute-counter to turn,
while the pinion 41 drives the wheel-and-pinion 42 and the wheel
44, which in turn drives the arbor 7.
Thus the arrangement described makes it possible to produce a
chronograph with a continuous slow-motion minute-counter in the
center. In this mechanism, when the chronograph members are
stopped, the normal hour- and minute-hands turn freely under the
action of the mainspring without being disturbed by the action of a
brake acting upon one of the chronograph wheels or pinions. The
setting of the hands 40 and 32 is made possible through the
friction existing between the wheel 31 and the collar 30 of the
cannon-pinion 28. The cannon-pinion 28 and the hour-wheel 38 may,
as a matter of fact, be driven independently of the wheel 31 owing
to that friction. In another embodiment, the minute-counter might
also be off-center. The wheel 35 might remain engaged with the
toothing 21 and drive the arbor of the counter by friction. Instead
of serving to pivot the pipe 33, the hour-wheel 38 would then
receive the pipe of the cannon-pinion 28 directly.
* * * * *