Winding up device for camera

Driving power of an electric motor is transmitted to wind up a photographic film on a spool and to charge the shutter and other mechanisms associated therewith. When the spool has wound up the film by one frame, the transmission of the driving power to the spool is cut off through a clutch mechanism. After the charge member has completed its operation of charging the shutter and the motor is de-energized, the clutch mechanism is rendered effective in response to return of the charge member to the initial position, whereby the transmission of the driving power to the spool is again ready to be performed.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to winding devices for cameras, and more 
particularly to a winding device for a camera such that when the exposure 
is terminated, winding of the photographic film and charging of the 
shutter and mechanisms associated therewith are performed by the action of 
one series of driving power so that the next exposure is ready to be 
performed. 
2. Description of the Prior Art 
In general, the winding device in a camera must change the angle of 
rotation of the spool for one-frame advancement of the film as the number 
of film frames exposed increases. This is because the diameter of the film 
wound on the spool is increased with decrease in the angle of rotation of 
the spool to advance the film through the length of one frame. 
Incidentally, the shutter and other mechanisms associated therewith are 
charged by an actuator which is required to always operate in a constant 
fashion regardless of the change of the frame number. Therefore, the 
conventional winding devices are generally constructed so that driving 
power of the driving means is transmitted directly only to the takeup 
spool to wind up the film thereon, and this moving film is used to drive a 
sprocket to rotate to a certain degree (necessary to move the film by one 
frame) by which the shutter is charged. In such winding device, however, 
as has been described above, the direct transmission of power from the 
driving source to the takeup spool is combined with the indirect 
transmission of the driving power to the charging mechanism for the 
shutter through the film, thereby making unavoidable increase in the 
complexity of the winding device. Another disadvantage is that so long as 
film is not loaded, the camera cannot be operated. 
In recent years, therefore, it has also been proposed to provide the 
winding device with a clutch mechanism operating in such a manner that 
while a certain amount of power from the driving means is transmitted 
directly to both of the takeup spool and the charging member for the 
shutter or the like, the transmission of the driving power to the takeup 
spool is cut off when the film is advanced one frame, thus changing the 
angle of rotation of the takeup spool depending upon the diameter of the 
film wound thereon. With such device, the above-mentioned problem that the 
lack of film leaves the camera in the idle state can also be eliminated. 
However, even such winding devices of the conventional type have 
alternative disadvantages, since the clutch mechanism for use in 
transmitting motion to the film is arranged to be closed or engaged 
(effective for transmission of the driving power) in response to either an 
actuation of camera release, or the termination of running down movement 
of the shutter. That is, in a case where the closing operation of the 
clutch mechanism is controlled by the release actuation, the actuator for 
releasing the camera must be designed to move through a longer stroke, or 
with a stronger force of depression, giving the user an unpleasant 
impression and increasing the possibility of producing drawbacks such as 
camera vibration. In the other case where the above-described closing 
operation of the clutch mechanism is coordinated with the closing 
operation of the shutter, as the shutter shares the available energy which 
must be large enough to change over the clutch mechanism, the shutter is 
apt to bind at the terminal end of the running down movement. 
Particularly, in an application of this winding device to lens 
shutter-equipped cameras, there is another disadvantage that because of 
the small kinetic energy of the shutter blades, the reliability of 
controlling the changing operation of the clutch mechanism is considerably 
lowered. 
The use of an electric motor as the driving means in such winding device 
also gives rise to an additional problem. That is, as the output of the 
motor is drivingly connected to the film transportation mechanism and the 
shutter charging mechanism, and the current supply to the motor is cut off 
when each cycle of charging operation is completed, it often happens that 
the feeding of the film from the cartridge terminates before the last film 
frame is fully advanced. If so, because of the fixture of the terminal end 
of the film strip to the supply spool in the cartridge, a further winding 
of the film is no longer possible, and the motor is braked hard while 
current flow thereto continues. This causes flow of a far larger current 
to the motor than when it rotates. Since the batteries used in the cameras 
are generally of small capacity, the allowance of such large current to 
flow results in a premature consumption of electrical energy in the 
battery. Further, when such a situation is permitted to exist for a long 
time, the motor and battery generate heat, causing accidental damage. 
In order to avoid such drawbacks, according to the prior art, upon making 
sure that the end of feeding of the film has occurred, the operator must 
manipulate a switch so that the current supply to the motor is cut off. 
With such construction and arrangement, however, the burden on the 
operator is increased, the management of the camera is complicated, and, 
when the necessary operation of the switch is overlooked, the 
above-described drawback is encountered. To avoid such difficulties in the 
operation of the camera, there has also been proposed a method of 
automatically cutting off the current supply to the motor by using, for 
example, an electrical delay circuit. This circuit is actuated when each 
cycle of film winding operation starts, and then produces a de-actuating 
signal for the current supply control switch only when that cycle is not 
completed within the prescribed time. The employment of this method, 
however, gives rise to problems in that provision must be made for an 
electrical control means in the form of the above-described delay circuit, 
and that the normal operation of the above-described delay circuit must be 
protected against a loss in the voltage of the battery by using an 
additional complicated circuit. It is, therefore, not compatible with a 
battery of small capacity such as is adapted to be accommodated in the 
camera housing. 
SUMMARY OF THE INVENTION 
With the foregoing in mind, it is an object of the present invention to 
provide a winding device for a camera with a clutch mechanism that renders 
it impossible to transmit the driving power to the spool therethrough when 
the spool takes up the film by one frame being arranged to establish the 
power transmission again when the charge member for charging the shutter 
and the like returns to the initial position, thus eliminating all the 
above-mentioned drawbacks of the conventional device and improving the 
reliability of winding control. 
Another object of the present invention is to provide a winding device of 
the type described above which does not unnecessarily use up electrical 
energy in the battery as the end of film feeding is detected in the form 
of a change in the output of the clutch mechanism and the current supply 
to the motor is automatically cut off. 
The various features of novelty which characterize the invention are 
pointed out with particularity in the claims annexed to and forming a part 
of this disclosure. For a better understanding of the invention, its 
operating advantages and specific objects attained by its use, reference 
should be had to the accompanying drawings and descriptive matter in which 
there are illustrated and described preferred embodiments of the invention 
.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 shows a motor driving circuit for a camera embodying the present 
invention. M is an electric motor for performing a film winding and 
shutter charging operation and E is an electrical power source for the 
motor M. S1 is a changeover switch controlling the film winding and 
shutter charging operation. When each cycle of winding operation is 
completed, the changeover switch S1 is set in a position where the winding 
of the motor M is short-circuited. When the winding operation is in 
progress, the electrical power source E is connected to the winding of the 
motor M. S2 is a normally closed switch arranged to be opened when the end 
of film feeding is detected as will be seen hereinafter, whereby the 
current supply to the motor M is cut off. 
FIG. 2 shows the construction and arrangement of the main parts of one 
embodiment of a camera according to the present invention in the film 
wound up position. Motion of the motor M is transmitted through a pinion 1 
affixed to the output shaft thereof, a gear 2 meshing with the pinion 1, 
and a further gear train G1 to a cutout gear 3. The cutout gear 3 rotates 
in a counterclockwise direction as viewed in FIG. 2 as the motor M rotates 
forward. When the gear 3 rotates, a rack 5 meshing therewith is driven to 
move in a direction indicated by arrow (a), while charging a shutter (not 
shown) and other mechanisms associated therewith. The cutout gear 3 is 
provided with a cam disc 4. When in the film wound up position shown in 
FIG. 2, a groove 4a formed in a portion of the periphery of the cam disc 4 
accepts a pawl 7a of a changeover lever 7 under the action of a spring 9. 
And, at this time, the changeover switch S1 is set by an actuator or end 
of the changeover lever 7 in the position where the poles of the motor M 
are short-circuited. The above-described lever 7 is pivotally mounted on a 
shaft 8. And, when the shutter has run down, a member 10 pushes the lever 
7 at one end 7c thereof against the force of the spring 9, whereby the 
lever is turned about the shaft 8 in the counterclockwise direction. Such 
movement of the change-over lever 7 causes disengagement of its pawl from 
the groove 4a of the above-described cam 4, and also causes its actuator 
end 7b to move the switch S1 to the position where the electrical power 
source E is connected to the motor M. 
On the other hand, motion of the motor M is also transmitted through the 
pinion 1, gear 2 and a gear train G2 to a gear 21. Underneath the gear 21 
there is a gear 22 of smaller diameter formed in unison therewith. This 
gear 22 meshes with a gear 23 which in turn meshes with a gear 24 and the 
gear 24 meshes with the gear 25. The gears 22 and 25 are mounted coaxially 
and rotatably independently of each other. Further arranged coaxially 
thereto is a clutch disc 26. And, mounted on this clutch disc 26 are the 
above-described gears 23 and 24. The gears 22 to 25 and the clutch disc 26 
form a so-called planetary gear train. 
The clutch disc 26 is provided with a saw-tooth like engagement portion 26a 
in the periphery thereof. When in the illustrated position, a bent 
engagement piece 35a formed in one end of a clutch lever 35 engages with 
one of the saw teeth 26a. With the clutch disc 26 latched by the clutch 
lever 35, it occurs that motion of the motor M is transmitted from the 
gear 21.fwdarw.gear 22.fwdarw.gear 23.fwdarw.gear 24.fwdarw.gear 25 and 
therefrom further transmitted through a gear train G3 to a film takeup 
spool 19. 
The clutch lever 35 is pivotally supported on one end 32a of a film feeding 
end detecting lever 32, and is biased by a spring 34 to turn in a 
counterclockwise direction, that is, in that direction which brings it 
into engagement with the clutch disc 26. The lever 32 is pivotally mounted 
on a shaft 31 and is urged by a spring 33 to turn in a counterclockwise 
direction until it abuts on a position defining pin 36. Therefore, the 
bias force of the spring 33 is applied as a constraining force between the 
clutch disc 26 and the lever 35 through the lever 32. It should be pointed 
out here that this constraining force is adjusted to be stronger than the 
torque occurring when the film winding operation is normal, but weaker 
than the torque resulting from the film feeding end. That is, the kinetic 
relationship at the periphery of the clutch disc 26 is set forth as 
follows: 
[The torque occurring when in the normal film winding mode]&lt;[The 
restraining force of the clutch lever 35 by the spring 33]&lt;[The torque 
occurring when the film is no longer fed] 
Upon fulfillment of such kinetic requirements, as will be described later, 
when in the normal film winding mode, the lever 32 assumes the position of 
FIG. 2. Then, when the cartridge no longer feeds film, the lever 32 is 
caused to turn in the clockwise direction against the bias force of the 
spring 33. 
37 is a holding lever for the switch S2 pivotally mounted on a shaft 38 and 
urged by a spring 39 in a clockwise direction. This lever 37 abuts with 
its one end 37a on the free end 32b of the lever 32, and its opposite end 
forms a bent-off portion 37b so that when the lever 32 is in the position 
of FIG. 2, the normally open switch S2 is pushed and held in the closed 
position. The end portion 37a of the holding lever 37 has its front edge 
formed to a recessed portion 37a' so that when the lever 32 changes its 
position to the clockwise direction, the lever 37 is rotated in the 
clockwise direction so long as the end portion 32b of the lever 32 drops 
into this recessed portion 37a'. Again, the end of the bent-off portion 
37b is provided with a display member 37c for which is provided a window W 
in the camera housing (not shown) to display when the film feeding comes 
to an end. And, when in the position of FIG. 2, the display member 37c 
cannot be seen through the window W. When the lever 37 is turned in the 
clockwise direction, the display member 37c is positioned in alignment 
with the window W. 
The clutch lever 35 is, as has been described above, urged by the spring 34 
in the counterclockwise direction with its pawl 35a being abutted against 
the engagement portion 26a of the clutch disc 26. At this time, the 
opposite end portion 35b of the clutch lever 35 is positioned opposite to 
a pushing pin 40b provided on one end of a slide 40. The slide 40 has a 
pair of longitudinally elongated slots 40c and 40c' which respective pins 
41 and 41' penetrate, thus being permitted to move in a prescribed range. 
A spring 42 urges the slide 40 to the left as viewed in FIG. 2. When each 
cycle of film winding operation is completed, this slide 40 is moved to 
the right by an actuator lever 16 against the force of the spring 42, 
while simultaneously turning the clutch lever 35 in the clockwise 
direction, whereby the clutch lever 35 and the clutch disc 26 are taken 
out of engagement with each other. 
The actuator lever 16 has one end pivotally mounted on a pin 15 which is 
fixedly mounted on one end of an L-shaped lever 11, with its opposite end 
provided with an actuator pin 16b for pushing the slide 40 at the end 
portion 40a. The differential lever 11 is pivotally mounted on a pin 12. 
The actuator lever 16 and differential lever 11 are urged by a spring 14 
having one end trained on a pin 16a provided at the center of the length 
of the lever 16 so that the actuator lever 16 turns about the pin 15 in a 
clockwise direction while the differential lever 11 turns about the pin 12 
in a counterclockwise direction. One end 11a of this differential lever 11 
abuts on a pin 5a provided at a predetermined point of position on the 
rack 5. Since, in the wound up position of FIG. 2, the rack 5 is returned 
to the rest position by the spring 6, the differential lever 11 is held in 
a clockwise deflected position by the pin 5a against the spring 14. On the 
other hand, the actuator lever 16 is deflected to a counterclockwise 
direction by a cam disc 17 abutting on the side edge thereof against the 
bias force of the spring 14. The cam disc 17 is affixed through a shaft 
17b to a sprocket 18 which engages with the perforations P of a film F so 
that when the film F is advanced one frame, it rotates one revolution. 
Formed in the cam disc 17 is a projected portion 17a at such a location 
that when in the wound up position of FIG. 2, the projected portion 17a 
abuts against the actuator lever 16. 
It is noted that 43 is a resetting slide movably mounted and guided by pins 
44 and 44' engaging in respective elongated slots 43c and 43c', and urged 
by a spring 45 to move in a leftward direction. After all the film frames 
have been exposed, when the camera is switched to the rewinding mode, the 
slide 43 is moved to the right, whereby the holding lever 37 is turned in 
a counterclockwise direction in engagement with a pushing pin 43a, and at 
the same time the slide 40 is moved to the right in engagement with a 
pushing pin 43b. 
In operating the camera of such construction, when the shutter is closed, 
the member 10 turns the changeover lever 7 in the counterclockwise 
direction, whereby the pawl 7a is disengaged from the groove 4a, and at 
the same time the switch S1 is moved to supply the motor M with current 
from the battery E. Then, the motor M starts to rotate. As the motor M 
rotates, the cutout gear 3 is rotated and, as shown in FIG. 3, the rack 5 
is moved in the direction of arrow (a), whereby the shutter (not shown) is 
charged. At the same time, motion of the motor M is also transmitted to 
the spool 19. As the spool 19 rotates, the film F is wound up on the spool 
19. Such movement of the film F causes counterclockwise rotation of the 
sprocket 18 in engagement with the perforations P of the film F. As this 
sprocket 18 rotates, the cam disc 17 is also rotated to move the projected 
portion 17a away from the lever 16, permitting the actuator lever 16 to 
turn about the shaft 15 in the clockwise direction under the action of the 
spring 14. On the other hand, as the rack 5 moves, the differential lever 
11 is turned about the shaft 12 in the counterclockwise direction under 
the action of the spring 14 until it abuts against the position defining 
pin 13. Such movement of the differential lever 11 causes leftward 
movement of the actuator lever 16 so that the actuator pin 16b is 
positioned in alignment with the end portion 40a of the slide 40 as shown 
in FIG. 3. Then, when the film F is advanced by one frame, the cam disc 17 
rotates one revolution, bringing its projected portion 17a into abutting 
engagement against the side edge of the lever 16 again and then turning 
the lever 16 in the counterclockwise direction as shown in FIG. 4. 
Therefore, the actuator pin 16b pushes the slide 40 at the end 40a to the 
right against the force of the spring 42, which in turn causes the clutch 
lever 35 to turn about the shaft 32a in the clockwise direction against 
the force of the spring 34 as the pushing pin 40b is acted on one end 35b 
of the clutch lever 35. As a result, the pawl 35a of the clutch lever 35 
is taken out of engagement with the toothed portion 26a of the clutch disc 
26. Then, the clutch disc 26 is rendered freely rotatable so that the 
driving torque of the motor M is no longer transmitted to the gear train 
G3. Thus, the film F is stopped from being further wound up. 
On the other hand, the cutout gear 3 continues rotating. Then, when the 
shutter is charged, the cutout portion of the gear 3 comes to alignment 
with the rack 5, whereupon the rack 5 is returned to the position of FIG. 
2 by the action of the spring 6. As a result, the detent pawl 7a of the 
changeover lever 7 drops in the groove 4a of the cam disc 4, permitting 
the switch S1 to be moved to the position of FIG. 2 again where the motor 
M is de-energized. Meanwhile, as the rack 5 returns to the position of 
FIG. 2, the differential lever 11 is turned in the clockwise direction, 
whereby the actuator pin 16b is moved away from the path of movement of 
the end portion 40a of the slide 40. Then, the slide 40 is returned to the 
position of FIG. 2 under the action of the spring 42, and the clutch lever 
35 is also turned in the counterclockwise direction by the force of the 
spring 34 and engages with the clutch disc 26 again. Thus, the camera is 
made ready to the next exposure for one film frame. 
It is noted that though the foregoing explanation is valid provided that 
the film F is loaded in the camera, it is valid even without the loading 
of the film F in the camera in that the cutout gear 3 operates similarly. 
Therefore, charging of the shutter through the rack 5 is effected likewise 
as in the above-described case. 
Now assuming that, in the camera of the above-described construction, the 
cartridge no longer feeds the film, then because of the fixture of the 
terminal end of the film to the hub of the cartridge, the spool 19 cannot 
further rotate and is stopped leaving the motor M supplied with current. 
Therefore, a high torque is applied to the gear train in the winding up 
system. At this time, however, the clockwise torque of the clutch disc 26 
is transmitted through the clutch lever 35 to the lever 32. Since the bias 
force of the spring 33 for the lever 32 has a smaller value than that 
torque occurring when the film is no longer fed, the lever 32 is turned in 
the clockwise direction against the force of the spring 33 as shown in 
FIG. 5. Then, along therewith, the holding lever 37 is turned in the 
clockwise direction until its recessed portion 37a' engages with the end 
portion 32b of the lever 32. As a result, the switch S2 is opened, thus 
cutting off the current supply to the motor M. And, the display member 37c 
appears in the window W, informing the operator of the fact that there is 
no more film. 
It is noted that when the camera is switched from this winding mode to the 
rewinding mode, the resetting slide 43 is moved in a direction indicated 
by arrow (c). As the slide 43 moves in the (c) direction, the slide 40 is 
moved in the direction of arrow (b). Therefore, the pushing pin 40b turns 
the clutch lever 35 in the clockwise direction, whereby the detent pawl 
35a is disengaged from the clutch disc 26. Further, the pin 43a provided 
on the slide 43 turns the holding lever 37 in the counterclockwise 
direction, whereby the lever end 37a' is disengaged from the lever end 
32b. Then the film feeding end detecting lever 32 is returned to the 
position of FIG. 2 by the action of the spring 33, and the holding lever 
37 is also returned to the position where the switch S2 is closed. 
Therefore, the display member 37c disappears from the window W. Thus, the 
camera is reset from the filming end detecting mode by rewinding the film. 
As has been described in detail, the present invention contemplates the use 
of the charge member for the shutter in changing over the clutch mechanism 
with the advantage that there is no need to use surplus driving power and 
activation as compared with a conventional device which cooperates with 
the release actuator or with the shutter blades, thus eliminating the 
drawbacks of the conventional device, whereby a positive operation can be 
expected. Another advantage of the invention is that since the current 
supply to the driving means, that is, the motor is controlled in such a 
manner that when the spool is stopped midway by the shortage of the film 
in the cartridge, the resultant increase in the torque of the clutch 
mechanism is detected to cut off the current supply to the motor. Thus, 
there is eliminated the possibility of occurrence of an accident due to 
the wasteful consumption of electrical energy in the battery and heat 
generation which would otherwise result from the flow of an excessive 
current to the motor when the film is no longer fed. A further advantage 
of the invention is that since a display representing the film end is 
presented at the same time when the current supply to the motor is 
interrupted, the photographer is not only informed of the fact that the 
film has to be replaced, but is also able to clearly discriminate that 
fact from an accidental stoppage of the current supply due to, for 
example, breakage of the wiring. A further advantage of the invention is 
that since the current supply to the motor is controlled by mechanical 
means, the provision of a delay circuit and a switching circuit as in the 
conventional device is not necessary and therefore the premature 
consumption of the battery can be avoided. Also, the electrical energy in 
the battery can be effectively used with the limitation being only for 
essentially required operation such as film winding. Another advantage of 
the invention is that since the film end is detected by utilizing the 
force exerted in the driving torque transmission mechanism when the spool 
is stopped midway, the structure of the film end detecting mechanism can 
be simplified. 
While specific embodiments of the invention have been shown and described 
in detail to illustrate the application of the inventive principles, it 
will be understood that the invention may be embodied otherwise without 
departing from such principles.