Dual floating gear system for a film transport mechanism

A film transporting apparatus for moving film between a film cartridge and a take-up spool includes a bi-directional motor rotatable in a first direction and a second direction opposite to the first direction, a driving gear engaged with the motor and rotatable in a first and a second direction in response to the direction of rotation of said motor, and a pair of displaceable gears engageable with said driving gear for selectively engaging said film cartridge. According to the invention, each of the pair of displaceable gears is independently movable so as to move into and out of engagement with the film cartridge depending on the direction of rotation of the bi-directional motor to allow either winding and rewinding of film out of and into the cartridge. In a preferred arrangement, the displaceable gears are each movable along a slotted path provided in the camera frame.

FIELD OF THE INVENTION 
The invention relates generally to the field of photography, and in 
particular to cameras having motorized film transport mechanisms for 
winding and rewinding film. 
BACKGROUND OF THE INVENTION 
It is conventionally known in the field of photography to use a contained 
single bi-directional motor for winding and rewinding photographic film in 
a 35 mm camera. For example, in commonly assigned U.S. Pat. No. 5,323,197, 
an associated gear train attached to the output pinion of the 
bi-directional motor interconnects the film cartridge spool and the take 
up spindle to cause film to either be pulled from the cartridge and onto 
the take-up spool, or to be rewound into the confines of the cartridge. 
The gear train includes a single swing gear which is selectively 
engageable with the film cassette spool to allow film rewinding depending 
on the direction of the motor. 
With the advent of so-called "thrust" type film cartridges, such as those 
described in U.S. Pat. Nos. 5,359,378, 5,248,108, and 5,031,855, among 
others, film transport systems have been provided which allow film to be 
initially driven or thrust from the interior of the cartridge for winding 
of the film onto the take-up spool, rather than requiring a user or 
manufacturer to first cinch an extending leader portion of the filmstrip 
onto the takeup spool before energizing the bi-directional motor to wind 
the film. In U.S. application Ser. No. 07/678,216, a gear train includes a 
pair of movable gears which are separately engageable with the film 
cartridge spool to allow film to be thrust from the cartridge and onto the 
take-up spool, or to allow film to be rewound. The gears are each in 
rotational contact with a driving gear and are connected to each other by 
means of an extension arm. This arm is pivotable to allow one of the swing 
gears to engage the film cartridge spool when the output pinion of the 
motor is rotated in a film advancing direction, thereby creating the 
thrust mode, and the other swing gear to engage the film cartridge spool 
when the output pinion is rotated in a film rewinding direction, allowing 
film rewinding. Additional parts, particularly the pivotable extension 
arm, must be added to the camera, adding increased cost and size thereto, 
and in which savings in cost and material are always desirable. 
SUMMARY OF THE INVENTION 
The present invention is directed to overcoming one or more of the problems 
set forth above. Briefly summarized, according to one aspect of the 
present invention, there is provided an apparatus for moving a filmstrip 
between a film cartridge and a takeup spool comprising a bi-directional 
motor rotatable in a first direction and a second direction opposite the 
first direction; a driving gear engaged with said motor which is rotatable 
in a first and a second direction depending on the rotation of said motor; 
and a pair of displaceable gears engaged with said driving gear and 
selectively engageable with said film cartridge, characterized in that: 
each of said displaceable gears are independently movable to allow movement 
into and out of engagement with the film cartridge for winding and 
rewinding of film out of and into the cartridge. In a preferable 
configuration, each of the displaceable gears are movable along a slotted 
path. 
By allowing independent movement of each of the swing gears to selectively 
move into and out of engagement with the cartridge driving elements, 
particularly by providing slotted paths for the gears in the camera body, 
as opposed to a swing plate or other attachment means, there are realized 
savings in the size and cost of an associated camera. 
These and other aspects, objects, features and advantages of the present 
invention will be more clearly understood and appreciated from a review of 
the following Detailed Description of the Preferred Embodiments and 
appended claims, and by reference to the accompanying Drawings.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIG. 1, a film transporting apparatus 10 is illustrated which 
includes a bi-directional motor 12 operatively connected to a take-up 
spool 14 and coupled to a film cartridge film spool contained within a 
thrust-type film cartridge 16. 
The film transporting apparatus 10 is contained within the body of a 
photographic camera, a portion of which is shown in FIG. 1. Additional 
discussion as to these and other features common to camera do not form a 
part of the present invention, and are therefore not required. Thrust type 
film cartridges, such as those described more specifically in commonly 
assigned U.S. Pat. Nos. 4,938,429 and 5,200,777 are also known to those of 
ordinary skill in the field and require no further specific description 
with regard to the present invention. Specific details, however, 
pertaining to the cartridge and operation of the cartridge can be found in 
the above noted patents, which are hereby incorporated by reference. 
The bi-directional motor 12 is adapted to rotate in a first direction to 
wind a photographic film 13 onto the take-up spool 14 and to rotate in a 
second direction opposite the first direction to wind the photographic 
film onto a film spool (not shown) in the film cartridge 16. A 
conventional control circuit (not shown) is adapted to activate and to 
cause the bi-directional motor 12 to rotate in its first and second 
directions. 
A motor pinion gear 20 is connected to a motor shaft 22. The motor pinion 
20 is in mesh engagement with a gear 24 having an integral pinion gear 26 
which is in mesh engagement with a gear 28. Gear 28 includes an integral 
pinion gear 29, FIG. 2, which is in mesh engagement with a gear 30. A 
pinion gear 31 is made integral with the gear 30, and in mesh engagement 
with a gear 32. Gear 32 is in mesh engagement with a take-up spool gear 
34, via pinion gear 33, and attached to the take-up spool 14, This gear 
train 23 causes a photographic film strip 58 to be wound onto the take-up 
spool 14 in response to the bi-directional motor 12 rotating in its first 
direction, 
The take-up spool 14 can include any conventional means for capturing the 
photographic film. For example, at least one hook 60 projecting above the 
periphery of the take-up spool 14 engages a film perforation 62 in the 
photographic film 58. 
According to the present invention, the pinion gear 33 is also in mesh 
engagement with a gear 36, as best illustrated in FIG. 1, which is in mesh 
engagement with a gear 38. The gear 38 is in mesh engagement with a gear 
40 having a pinion gear 42. The pinion gear 42 is in mesh engagement with 
a gear 43, shown only in FIG. 1, which is in mesh engagement with a 
driving gear 44 in mesh engagement with a pair of displaceable gears 46, 
48. The driving gear 44 is adapted to rotate in a first direction and a 
second direction in response to rotation of the bi-directional motor 12 in 
its first and second directions, respectively. 
Each of the displaceable gears 46, 48 are adapted to rotate around the 
driving gear 44 along a predetermined path between a first position, where 
either displaceable Gear is disengaged from a spindle gear 54, and a 
second position, shown in phantom in FIG. 1, where either of the gears 46, 
48 are in mesh engagement with the spindle gear 54 in response to rotation 
of the driving gear 44 in its first direction and its second directions, 
respectively. The spindle gear 54 is attached to the film spool (not 
shown) in the thrust film cartridge 16. Details of the thrust components 
are described in the U.S. Pat. Nos. 4,938,429 and 5,200,777 which were 
incorporated specifically by reference above. 
According to the preferred embodiment of the present invention, the 
predetermined path of each of the displaceable gears 46, 48 is defined by 
respective channels or slots 50, 51, shown in FIG. 2, formed in a housing 
or gear plate 72 and in the cover plate (not shown) of the camera. Each of 
the displaceable gears 46, 48 include a shaft 74 protruding above and 
below each displaceable gear. The protruding ends of the shaft 74 rotate 
within the channels 50, 51 and are confined therein as each of the 
displaceable gears 46, 48 rotate around the driving gear 44. 
Turning to the diagrammatic FIGS. 2-4, the method of operation of the film 
transporting apparatus 10 will now be described. For purposes of the 
following discussion, the gear 43, shown in FIG. 1, is removed from the 
illustrated gear train 23. Therefore, for compactness the driving gear 44 
is in mesh engagement with the pinion gear 42. 
Referring now specifically to FIG. 2, the filmstrip 13 is thrust from the 
cartridge 16 by initiation of the bi-directional motor 12, via activation 
of the control circuit (not shown), such as by an external switch (not 
shown) on the body of the camera. The motor 12 and thereby the output 
motor shaft 22 is caused to rotate in a first (clockwise, according to 
this embodiment) direction, per arrows 70, engaging the pinion gear 20 and 
causing each of the components of the gear train 23 to rotate in a 
complementary fashion. Respective rotations of the drive components of the 
gear train 23 cause the take-up gear 34 to rotate in a counterclockwise 
(as shown) film winding direction, due to the engagement of gear 32. 
On the other side of the gear train 23, gear 38 engages gear 40 and 
integral pinion gear 42 engages the driving gear 44, causing the driving 
gear 44 to rotate in a counterclockwise direction. The counterclockwise 
rotation of the driving gear 44 causes each of the displaceable gears 46, 
48 to rotate in and translate in a counterclockwise fashion, thereby 
moving each of the displaceable gears 46, 48 within their respective 
channels 50, 51, bringing the first displaceable gear 46 into engagement 
with the spindle gear 54, and causing the spindle gear to rotate in a 
counterclockwise direction. Rotation of the spindle gear 54 as described 
causes the photographic film 13 contained within the cartridge 16 to 
unwind from the spool (not shown) and be thrusted from the cartridge 16, 
as shown by arrow 66. In the meantime, the second displaceable gear 48 
remains engaged with the driving gear 44, but is not engaged with the 
spindle gear 54. 
Referring more specifically to FIGS. 1 and 3, the leading portion of the 
filmstrip 13 advances where it is taken up by the rotating take-up spool 
14, in a conventional manner, such as by engagement of the perforations 62 
with the extending hooks 60. The takeup spool 14, due to the gearing ratio 
of the described gear train 23, is preferably rotating at a faster speed 
than the spindle gear 54, therefore, once the filmstrip 13 is taken up by 
the take-up spool 14, the film 13 is pulled from the film cartridge 16 at 
a faster rate than previously imparted to the spindle gear 54 by the 
driving gear 44. The corresponding increase in speed of the cartridge 
spool(not shown) as the film 13 is pulled therefrom is imparted to the 
spindle gear 54, causing the first displaceable gear 46 to be overridden, 
or slipped from engagement with the spindle gear, as shown by arrows 76. 
In summary, and upon cinching of the film 13 with the take-up spool 14, 
there is no longer a drive component acting on the film cartridge 16 from 
the gear train 23. Instead, the filmstrip 13 is withdrawn from the 
cartridge 16 solely due to the rotation and pulling action of the takeup 
spool 14, and not from the thrust action supplied to the spindle gear 54 
and cartridge 16 by the bi-directional motor 12 and associated gear train 
23. Subsequently, as the filmstrip 13 is being advanced in a frame by 
frame manner across the film gate of the camera (not shown) in a manner 
conventionally known, the filmstrip is not being thrust from the cartridge 
16 by the engagement of the driving gear 44 and first displaceable gear 46 
with the spindle gear 54, but is pulled by the rotation of the takeup 
spool 14. 
Referring now to FIGS. 1 and 4, the rewind mode of the film transporting 
apparatus 10 is shown according to the present embodiment. 
During the rewinding phase, the external switch or other equivalent means 
triggers the control circuit (not shown), activating the bi-directional 
motor 12 and causing the output shaft 22 to rotate in a counterclockwise 
direction, as shown by arrows 78. By complementary engagements with the 
respective elements of the gear train, the counterclockwise rotation of 
the output motor shaft 22 causes the driving gear 44 to rotate in a 
clockwise direction. Each of the engaged first and second displaceable 
gears 46, 48 are caused to translate in a clockwise fashion within their 
respective channels 50, 51 so that now the second displaceable gear 48 
engages the spindle gear 54, causing the spindle gear to also rotate in a 
clockwise direction, or film rewinding direction which is imparted to the 
film spool (not shown). The film 13 is then rewound according to the 
direction shown by arrow 68 from the take-up spool 14 to the confines of 
the film cartridge 16. 
Similarly, the counterclockwise rotation of the motor 12 and output shaft 
22 causes the take-up spool gear 34 to also rotate in a clockwise or film 
rewinding direction. 
During rewind, the film spool (not shown) of the cartridge 16 is powered by 
the action of the motor 12 and the associated gear train 23 due to the 
engagement of the second engagement gear 48 with the spindle gear 54. In 
the meantime, the first displaceable gear 46 while engaged with the output 
gear 44 remains unengaged relative to the spindle gear 54 and the film 
cartridge 16. 
The invention has been described with reference to a preferred embodiment. 
However, it will be appreciated that variations and modifications can be 
effected by a person of ordinary skill in the art without departing from 
the scope of the invention. 
TS LIST 
10 film transporting apparatus 
12 bi-directional motor 
13 photographic film or filmstrip 
14 take-up spool 
16 film cartridge 
20 motor pinion gear 
22 motor output shaft 
23 gear train 
24 gear 
26 integral pinion gear 
28 gear 
29 integral pinion gear 
30 gear 
31 integral pinion gear 
33 pinion gear 
32 gear 
34 take-up spool gear 
36 gear 
38 gear 
40 gear 
42 pinion gear 
43 gear 
44 driving gear 
46 first displaceable gear 
48 second displaceable gear 
50 slot/channel 
51 slot/channel 
54 spindle gear 
58 filmstrip 
60 hooks 
62 perforations 
66 arrow 
68 arrow 
72 gear plate 
74 shaft 
76 arrow 
78 arrow