JPH0442632U - - Google Patents

Description

[Brief explanation of the drawing]

Figure 1 is a plan view showing one embodiment of the present invention, Figure 2 is a plan view showing one embodiment of the present invention;
The figure is an enlarged view showing the relationship between the radius of curvature of the turning locus of the cam edge contact point of the set roller and the curvature radius of the turning locus of the cam edge contact point of the return prevention pin, and the relationship between the curvature radius of the set roller and the curvature radius of the return prevention pin. FIG. 3 is a plan view showing the state immediately before the set bar is lowered, FIG. 4 is a plan view showing the initial hold state,
Figure 5 is an explanatory diagram of the case where the hold state can be maintained even if an overrun occurs at the set position, and Figure 6 is an explanatory diagram of the case where interference with the cam arm can be prevented even if a reverse occurs when the set bar is released. , FIG. 7 is a plan view showing another embodiment of the present invention. 1... Lead blade drive lever, 5... Trailing blade drive lever, 8... Set bar, 8f... Cam edge, 12
...Cam gear, 12b...Set roller, 12c
...Return prevention pin, 12d...Return prevention cam.

Claims (1)

[Claims for Utility Model Registration] (1) A blade drive member connected to a shutter blade and urged in a direction to expose the shutter blade, and traveling in a direction to move the blade drive member to a set position. a setting member that is biased in a direction opposite to the direction in which the blade driving member is moved to the set position; The arc-shaped cam edge receives a force that moves it in the direction of movement, and the rotation of the motor, which rotates in one direction, is transmitted and rotates, and the radius of curvature of the turning trajectory of the cam edge contact point is a set roller having a radius of curvature equal to the radius of curvature of the arcuate cam edge, which moves the set member to a set position of the blade driving member by contacting the cam edge, and releases the set member by moving away from the cam edge; and a rotating member having a rotary member, the blade driving member is held at the set position by stopping the rotating member while the set roller is in contact with the arc-shaped cam edge, and the set roller is In the drive mechanism for a camera shutter, the setting member is released by stopping the rotating member in a state where the rotating member is separated from the arc-shaped cam edge, and the rotating member is provided with a rear part of the setting roller. A return prevention member is disposed at a location where the distance from the set roller is shorter than the width of the arcuate cam edge, and the return prevention member prevents the set member from returning from the set position of the blade drive member. A camera shutter drive mechanism featuring: (2) Utility model registration In the camera shutter drive mechanism according to claim 1, the return preventing member is located behind the set roller on the rotating member and has a distance from the set roller in the arc shape. A drive mechanism for a camera shutter, characterized by a return prevention pin implanted at a point shorter than the width of the cam edge. (3) In the camera shutter drive mechanism according to claim 1 or 2 of the utility model registration claim, the blade drive member is capable of being overcharged beyond the set position, and the cam edge of the return prevention member A drive mechanism for a camera shutter, characterized in that a radius of curvature of a turning locus of a contact point is smaller than a radius of curvature of a turning locus of a cam edge contact point of the set roller by an amount of overcharge of the blade drive member. (4) Utility model registration The camera shutter drive mechanism according to claims 1 to 3, characterized in that the radius of curvature of the rear end of the return preventing member is smaller than the radius of curvature of the set roller. A drive mechanism for camera shutters.