Contact mechanism of shutter for camera

A camera shutter mechanism comprises opening and closing members sequentially movable to open and closed positions to accordingly effect opening and closing of a shutter aperture to complete an exposure. The opening member engages with a contact member to move the contact member into electrical contact with a stationary contact member during movement of the opening member into its open position and the opening member returns to its initial position during the course of movement of the closing member to its closed position.

BACKGROUND OF THE INVENTION 
This invention relates to improvements in the contact mechanism of a 
shutter for a camera. Among contacts for ensuring an electrically 
conductive state during the exposure operation of a shutter, there are a 
synchronizing contact for making a flashing apparatus light, a holding 
contact for connecting the power supply of an electronic shutter to the 
network, etc. 
In a shutter of the type which carries out the exposure operation with one 
set of shutter blades, it is relatively easy to structure the contact. In 
a shutter which carries out the exposure operation with two sets of 
shutter blades, on the other hand, it is necessary to arrange the contact 
so that it closes during the course of the opening operation and opens 
during the closing operation, resulting in rather complicated structure of 
said contact, limited space in arrangement, etc. 
SUMMARY OF THE INVENTION 
The principal object of this invention is to provide a shutter contact 
arrangement of simple structure for use with a shutter having two sets of 
shutter blades and the structure thereof consists fundamentally in an 
operation for opening and closing a contact member in response to movement 
of the opening member only, which after the completion of the closing 
operation returns towards the initial direction. Referring now to the 
accompanying drawings, the invention will be described in detail as 
follows.

DETAILED DESCRIPTION OF THE INVENTION 
In FIG. 1 a shutter base plate 1 is provided with an exposure opening (not 
shown), on which various members to be described below are arranged. An 
opening member 2 is rotatably pivoted on a shaft 2a and has a pin 2c on 
which a spring 2b exerts a right-turning force biasing the member 2 in the 
clockwise direction in FIG. 1. A stop pin 2e is positioned to engage a 
projection 2d at the other end of the opening member 2. Said opening 
member 2 is interlocked with shutter blades (not shown) and is shown in 
the drawing in a first position wherein said shutter blades cover said 
opening. A hook member 3 for releasably locking said opening member 2 is 
rotatably pivoted on a shaft 3a, and is biased rightwardly by a 
right-turning spring (not shown) and a hook portion 3b locks said 
projection 2d of said opening member 2. 
A closing member 4 is rotatably pivoted on a shaft 4a and has a pin 4c on 
which a right-turning spring 4b exerts a clockwise bias and is provided 
with a stop pin 4e which controls the operation of a projection 4d at the 
other end thereof. Said closing member 4 is interlocked with said shutter 
blades (not shown) and is show in the drawing in a second position wherein 
said shutter blades uncover said opening. 
A hook member 5 for releasably locking said closing member 4 is rotatably 
pivoted on a shaft 5a and is biased rightwardly by a right-turning spring 
(not shown) and a hook portion 5b locks said projection 4d of said closing 
member 4. 
An actuating member 6 is operatively supported on the base plate 1 by means 
of a fixed pin 6b slidably fitted in a slot 6a formed near the lower part 
of said member 6, said member 6 is pressed upwards and leftwards by a 
spring 6c and a hook portion 6d locks a fixed locking pin 6e. The 
actuating member 6 has a step portion 6f for locking with said pin 2c of 
said opening member 2, a step portion 6g succeeding said step portion 6f 
and a step portion 6h for locking with said pin 4c of sid closing member 
4. 
A contact member 7 is fitted on said shaft 2a of said opening member 2 and 
is pressed by a left-turning spring 7b and is provided with an 
upward-projecting pin 7c for releasably locking with said opening member 
2. 
One end of said contact member 7 is provided with an electric contact 
portion 7d, which forms a counterpart of a contact piece 7e which is 
electrically insulated and fixed in opposition thereto. Said contact 
member 7 is at rest in contact with a pin 7f. Now, the operation of the 
shutter according to this invention will be briefly described. 
During the course of the release operation, said hook member 3 for said 
opening member 2 is turned to the left from the state shown in FIG. 1 
whereby said hook portion 3b is unlocked from said projection 2d to enable 
turning of said opening member 2 to the right by said spring 2b. This 
turning of said opening member 2 shifts said shutter blades (not shown) 
from the first position covering said opening to the second one uncovering 
said opening and initiates the taking of the exposure. 
In the region wherein the opening member 2 finishes its operation, said 
opening member 2 engages with said pin 7c of said contact member 7 to move 
said contact portion 7d of said contact member 7 into contact with said 
contact piece 7e and thereafter said projection 2d comes into contact with 
said pin 2e to complete the operation. FIG. 2 shows the state at this 
moment. 
After the lapse of a desired exposure time by a well-known method (not 
shown in the drawing), said hook member 5b for said closing member 4 turns 
to the left to unlock said member 5b from said projection 4d whereupon 
said closing member 4 turns to the right by means of said spring 4b to 
shift said shutter blades (not shown) from the second position uncovering 
said shutter opening to the first one covering said opening to complete 
the exposure. 
In the region wherein the closing member 4 finishes its operation, said pin 
4c engages with said step portion 6h to push rightwards said actuating 
member 6 against said spring 6c and to unlock said hook portion 6d from 
said pin 6e, so that said actuating member 6 is displaced upwards by said 
spring 6c. Upon engagement of said step portion 6f with said pin 2c and of 
said step portion 6g with said pin 7c, the state shown in FIG. 3 is 
realized. Consequently, said shutter blades operated by said opening 
member 2 again return to said first position and said contact portion 7d 
comes out of contact with said contact piece 7e. 
FIG. 4 shows the second embodiment, and shows the state where said shutter 
blades are open. In the drawing there is shown the contact state of a 
contact portion 47d of a contact member 47 with a contact plate 47e after 
an opening member 42 turns to the right by the action of a spring 42f to 
open a shutter blades and to push said pin 47c of said contact member 47, 
said opening and closing memnbers 42 and 47, respectively, being as shown 
in FIG. 4. When after the lapse of the desired exposure time said closing 
member 74 turns to the right by the action of said spring 74f, said 
shutter blades are closed to complete the exposure and then said 
projection 74d pushes said projection 42d to make said opening member turn 
to the left against said spring 42f so that said contact portion 47d comes 
out of contact with said contact piece 47e, resulting in the completed 
operation of said closing member 74. 
FIG. 5 shows the third embodiment and shows the state immediately after the 
completion of an exposure operation. In the drawing, there is shown a 
state where a projection 75d pushes a bent portion 10b of a connecting 
member 10 to unlock an engaging portion 10a of said connecting member 10 
from a bent portion 52c against a spring 10f, whereby said member 10 turns 
to the right to open said shutter blades and said closing member 75 
further turns to the right by the action of a spring 75f to close them 
resulting in the completion of the exposure, the mechanism shown in FIG. 5 
being composed in the same manner and having the same mode of operation as 
the mechanism described in earlier-filed U.S. Pat. application Ser. No. 
708,026, now U.S. Pat. No. 4,054,891. By the action of a spring 52f, 
opening member 52 instantaneously turns to the left from the state shown 
in the drawing to release the pressure of a pin 57c so that said contact 
portion 57d comes out of contact with said contact plate 57e, resulting in 
the completion of the operation. 
In FIG. 6, the arrangement is such that a contact portion 62g placed on an 
opening member 62 is equivalent to the FIG. 4 arrangement of said contact 
member 47 and said opening member 42 and the contact portion 62g comes 
into contact with an insulated contact plate 62a. 
In FIG. 7, said contact plate 62a in the embodiment of FIG. 6 is arranged 
as a contact plate 62j so that it is conductive before the operation of 
said opening member 62 and is shifted to be nonconductive when said member 
62 operates but returns again to the initial conductive state. Before the 
operation of said opening member 62, contact portion 62i and contact plate 
62j are kept conductive, and when said opening member 62 starts to 
operate, they are shifted to be nonconductive as shown in FIG. 7. When 
said opening member 62 returns after the completion of the exposure 
operation, said contact portion 62i again comes into contact with said 
contact plate 62j to return the conductive state. 
In connection with the opening operations of said opening members 2, 42, 52 
and 62, as mentioned above, they are made to return to their respective 
states before operation by making said contact portions 7d, 47d, 57d and 
62g come into contact with said contact plates 7e, 47e, 57e and 62h, 
respectively, or by making said contact portion 62i come out of contact 
with said contact plate 62j and when the operations of said closing 
members 4, 74, 75 and 64 are completed, by making said opening members 2, 
42, 52 and 62, respectively, travel for resetting so as to interrupt said 
contact or making said contact portion 62i come into contact with said 
contact plate 62j. 
Travelling of said opening member for the resetting operation is not 
limited to the heretofore disclosed techniques and it is possible to make 
said opening member travel for resetting if a spring operating said 
opening member is made to return its direction after the operation of said 
closing member to act thereon, as is disclosed in earlier-filed U.S. 
patent application Ser. No. 712,400; or to make the same if said spring 
operating said closing member acts on said opening member; or to make the 
same if when the operation of said closing member is inturrupted the 
inertial force acts said opening member. 
Since in said embodiments respective the contacts are closed at positions 
corresponding to the completion of the operations of said opening members, 
it is preferable that they are flash tuning contacts such as Storobo etc. 
and if the shutter according to this invention is arranged so as to close 
its contact at a position where said opening member starts to operate, it 
is also possible to adopt a tuning contact for a flashing apparatus with a 
long delay time or a contact for supplying electric power to the 
electronic shutter. 
If the contact for supplying electric power is adopted it is necessary to 
make its opening member travel for resetting to the initial position, in 
the case of the embodiment shown it is possible to interrupt the 
travelling for resetting once said contact comes out of contact. 
In this specification, each contact member is arranged so that it is 
shifted from nonconductive to conductive states but an arrangement wherein 
a contact member is shifted from conductive to nonconductive states is 
also possible. 
The travelling for resetting, after the completion of the exposure 
operation, of said opening member results in such advantages as the 
shutter blades having an improved light-shielding ability, reexposure can 
be prevented, shutter size can be reduced, etc.. 
It can thus be seen that the present invention makes it possible to 
complete the opening and closing operations of a contact member by 
connecting the opening and closing members only in a shutter where the 
exposure is finished through consecutive operations of the opening and 
closing members, and since the contact arrangement is extremely simplified 
and the connection with said closing member is unnecessary in comparison 
with the conventional opening and closing system of contact by means of 
connection of said contact member with both said opening and closing 
members, the degree of freedom in arrangement of said contact member is 
increased and as a result the size reduction of the shutter and 
stabilization of contact performance can be realized.